Shortly after the crews of the two tankers attacked this week in the Gulf of Oman evacuated their stricken vessels, the ships that rescued them were surrounded by Iranian military boats and told to transfer the mariners into their custody, according to declassified U.S. intelligence reports obtained on Friday by CBS News.

One of the civilian rescue ships eventually complied with the Iranian military's request. The other did not. The new details help to paint a picture of what happened Thursday in the Gulf, near the vital shipping channel of the Strait of Hormuz, through which about a third of the world's oil supply passes.

The U.S. has accused Iran of carrying out the attacks on the tankers — the second similar incident blamed on Iran in a month. Secretary of State Mike Pompeo called it "the latest in a series of attacks started by Iran and its surrogates against American and allied interests" aimed at "escalating tension."

He said the U.S. would defend its forces and interests in the region but gave no specifics about any plans for retaliation, and he took no questions.

A U.S. defense official quickly dismissed an Iranian claim on Thursday, soon after the attacks, that Iran sent search teams that rescued 44 sailors from the two vessels. The official told CBS News that claim was "patently false," and that it was an American destroyer, the USS Bainbridge, that picked up 21 crew members from one of the vessels.

The intelligence reports obtained by CBS News on Friday include a readout from the crew of the Hyundai Dubai, an oil tanker that came to the rescue when the stricken Front Altair issued a distress call after an explosion on Thursday. The crew of the Norwegian-owned Altair came aboard the Hyundai Dubai, according to the detailed readout from the rescuing vessel's crew.

About 10 minutes later, the Hyundai Dubai "was surrounded by Iranian military vessels who demanded the Ship's Master turn over the M/V FRONT ALTAIR mariners," according to the readout.

The captain of the vessel contacted his company's management, which told him to refuse the Iranian request, but the readout says he "stated he felt like he had no choice but to comply with Iranian demands" and he did hand the Front Altair's crew over to the Iranian vessels. The sailors, most of them Russian and Filipino, were taken to Iran and remained in Iranian custody, the Front Altair's owner Frontline told Reuters on Friday.

The other tanker that came under attack on Thursday was the Japanese-owned Kokuka Courageous, which issued a distress call after sustaining an explosion that caused a fire in its engine room.

The readout from the crew of the Kokuka said a Dutch vessel responded and positioned itself to inspect the damage to the tanker.

"The Dutch vessel reported to the Master an unusual object on the Starboard side, mid-ship, of the KOKUKA. The crew looked over the side and noticed an object they believed to be an explosive. Due to the ship carrying methanol and already suffering one explosion, the Master ordered the crew to abandon ship," according to the intelligence briefing.

The Dutch vessel took the sailors from the Kokuka aboard and moved to a safe distance.

The crew of an Iranian military vessel then asked the Dutch ship for permission to board, "so they could transfer personnel and render assistance to the crew. The Master of the KOKUKA spoke to the owner of his vessel and was instructed not to go aboard the Iranian vessel so he declined aid and thanked them."

The crew of the Dutch vessel and the Kokuka were able to see attached to the tanker, as they moved away from it, a "grey explosive," described as being about five feet wide and three feet tall, which the sailors said was protruding from the hull, three to six feet over the waterline.

U.S. officials have accused Iran of using limpet mines in the attacks this week — the same magnetic explosive devices allegedly used by Iranians in attacks on four tankers in the region last month. The devices can be affixed to the hull of a vessel, and can cause significant damage to a ship. They have not, however, been powerful enough to breach the double hulled vessels sufficiently as to capsize them.

The U.S. military said Thursday it had a video showing troops from Iran's Revolutionary Guard removing an unexploded limpet mine from the Kokuka. The black-and-white video, as well as still photographs released by the U.S. military's Central Command, appeared to show a limpet mine on the Kokuka.

A U.S. official told CBS News senior national security correspondent David Martin on Friday that the U.S. had a forensic team aboard the Kokuka Courageous as it was being towed to port. Parts of the magnet which held the mine to the ship were still attached to the tanker's hull.

The official told CBS News that a commercial tug boat was sent to tow the Front Altair to port also, but that Iranian Navy vessels were preventing it from tying up to the tanker.

Why would Iran attack an oil tanker?

The waterways in the region are crucial to the global transportation of oil and gas: A third of all shipped oil comes through the area, and because the Strait of Hormuz, the narrow waterway near where the attack took place, is right off the coast of Iran, it's a point of leverage for the country.

Iran has repeatedly threatened to cut off this vital artery whenever there is a dispute with the U.S. or its regional allies, such as Saudi Arabia and the United Arab Emirates. Tension between Iran and the U.S. has mounted steadily since the Trump administration's unilateral withdrawal from the 2015 nuclear agreement negotiated by the previous occupant of the White House.

As CBS News reported in early June, the admiral of the USS Abraham Lincoln, an aircraft carrier in the region, said one of his ship's primary missions is to safeguard the free flow of commerce through the Strait and the surrounding waterways. The Lincoln was sent specifically because of perceived threats from Iran — but as CBS News correspondent Charlie D'Agata reported on Thursday, it doesn't appear to be proving much of a deterrent.

"On April 22nd, Iran promised the world it would interrupt the flow of oil through the Strait of Hormuz. It is now working to execute on that promise," Pompeo said Thursday.

Iran flatly denies any involvement in the tanker attacks, and has called the timing of Thursday's incidents "suspicious" as they came just as the Japanese leader was in Tehran trying to rekindle diplomacy.

Other nations, and the United Nations, have stressed the need to avoid "accidental" escalations in the region.

"I want to say how worried I am with the recent developments in the Gulf," United Nations Secretary-General António Guterres said on Friday. "We believe that the truth needs to be clearly established in relation to these attacks. We believe that responsibilities need to be clearly defined. And, as I said to the Security Council, the world cannot afford a major confrontation in the Gulf."

"It is very important to know the truth," Guterres said, before calling for "some independent entity" to verify the facts. He added that as secretary-general he cannot instigate an international investigation, but noted that the Security Council can. </s> • An oil tanker is on fire after it was hit by apparent attacks in the Gulf of Oman.
• A tanker owned by Norwegian company Frontline is on fire and the company that chartered the ship said it is “suspected of being hit by a torpedo,” but Frontline said that the crew is safe.
• A second tanker, also damaged in a “suspected attack,” has been evacuated, with one person injured.
• The US and UK Navies are responding to the incidents in the waters off Iran, an important oil-carrying route that has seen tensions between Iran and US tankers.

A photo shows an oil tanker on fire off the coast of Iran after two oil tankers in the region were hit by unexplained attacks.

The image, published by Iranian state media, shows the burning Front Altair, a tanker owned by Norwegian company Frontline that has now been evacuated.

Frontline told Reuters on Thursday that the shop was on fire but that its crew had been rescued. It denied reports that the ship sank.

Taiwan’s state oil refiner CPC, which had chartered the ship, said that it was “suspected of being hit by a torpedo.”

Bernhard Schulte Shipmanagement also told Reuters that a second tanker, the Kokuka Courageous was damaged, in a “suspected attack.”

The company said in a statement said that the 21 crew members “abandoned ship” after the ship’s hull was damaged. One cew member was “slightly injured,” it said.

Read more: Oil is surging after a suspected torpedo attack on 2 tankers in the Gulf of Oman

It said that the ship, which is 14 nautical miles from Iran’s coast, is “remains in the area and is not in any danger of sinking.” The methanol it was transporting, which is a flammable substance, is “intact,” it said.

The company said it has “launched a full-scale emergency response.”

A US Navy fleet said it was aware of a “reported attack” on the vessells after it recieved two separate distress calls. It said its ships are “in the area and rendering assistance.” Reuters reported that a part of the UK’s Royal Navy said it was investigating.

Oil prices are rising after the incident.

A source told Reuters that the Bernhard Schulte tanker may have been hit by a mine.

The US claimed earlier in June that Iran attacked four oil tankers with limpet mines, but Iran denies the charge.

The Gulf of Oman leads to the Strait of Hormuz, which is shared by Iran and Oman and where a third of the world’s oil passes through.

US ships travel through the area, though Iran has threatened to close it off and tensions have flared between the two countries with reports that oil tankers are being targeted. </s> Karim Sahib, AFP | An Emirati man looks on at the port of Fujairah in the Gulf Emirate, on May 13, 2019.

Two oil tankers were hit in suspected attacks in the Gulf of Oman and the crews have been evacuated, shipping firms and industry sources said on Thursday, a month after a similar incident in which four tankers in the region were struck.

The Bahrain-based US Navy Fifth Fleet said it was assisting the tankers after receiving distress calls following "reported attacks". The United Kingdom Maritime Trade Operations, part of the Royal Navy, said it was investigating.

Details of the incident were not immediately clear, but one operator said it suspected its ship had been hit by a torpedo. Another shipping firm said its vessel was on fire in the Gulf of Oman.

Iran’s official news agency IRNA reported that Iran’s navy had rescued 44 crew members from the tankers, and had transferred them to the port of Jask.

Oil prices surged by 4 percent after the report that has stoked tensions in the region that have already been heightened by attacks last month on Gulf oil assets amid a dispute between Iran and the United States over Tehran's nuclear programme.

The Gulf of Oman lies at the entrance to the Strait of Hormuz, a major strategic waterway through which a fifth of global oil consumption passes from Middle East producers.

There was no immediate confirmation from authorities in Oman or the United Arab Emirates, in whose territorial waters four tankers were hit last month. An investigation said limpet mines were used. US and Saudi officials blamed Iran for the May attack, a charge Tehran has denied.

Saudi Arabia and the UAE have said the attacks on oil assets in the Gulf posed a risk to global oil supplies and regional security.

On Thursday Bernhard Schulte Shipmanagement said tanker Kokuka Courageous was damaged in a "suspected attack" that breached the hull above the water line while on passage from Saudi Arabia to Singapore.

"The ship is safely afloat," it said in a statement.

Taiwan's CPC said tanker Front Altair, carrying 75,000 tonnes of naptha, was "suspected of being hit by a torpedo" around 0400 GMT. Refinitiv Eikon ship tracking data showed the Front Altair, an Aframax vessel owned by Norway's Frontline, had loaded naphtha, a petrochemical feedstock, and was in waters between Oman and Iran, carrying its cargo from Ruwais in the UAE to aiwan.

Frontline said its vessel was on fire in the Gulf of Oman.

The sources said crews from both vessels, which they had said had been struck in international waters, had been safely evacuated.

One shipping broker said there had been an explosion "suspected from an outside attack" that may have involved a magnetic mine on the Kokuka.

"All crew safely abandoned the vessel and were picked up by Vessel Coastal Ace. Kokuka Courageous is adrift without any crew on board,” the source said.

Another source said the Front Altair reported a fire caused by a "surface attack" and that the crew had been picked up by nearby vessel Hyundai Dubai. </s> Iranian gunboats reportedly tried to round up the crews of both tankers attacked Thursday in the Gulf of Oman, but were only able to take one crew into custody, according to a Fox News report and U.S. Central Command.

Sailors on the Front Altair were reportedly first rescued by the Hyundai Dubai, however, Iranian gunboats closed in and demanded the crew be turned over, U.S. Central Command said in a statement.

The statement said that aircraft dispatched to the attack site observed “an IRGC (Iranian Revolutionary Guard Corps) Hendijan class patrol boat and multiple IRGC fast attack craft/fast inshore attack craft (FAC/FIAC) in the vicinity of the M/T Altair.”

The statement said that the Iranian craft acted aggressively.

“(T)he Iranians requested that the motor vessel Hyundai Dubai, which had rescued the sailors from the M/T Altair, to turn the crew over to the Iranian FIACs. The motor vessel Hyundai Dubai complied with the request and transferred the crew of the M/T Altair to the Iranian FIACs,” the statement said.

In the meantime, the statement said 21 sailors from the Kokuka Courageous were picked up by the Coastal Ace, a Dutch tugboat, and then transferred to the destroyer USS Bainbridge.

“While the Hendijan patrol boat appeared to attempt to get to the tug Coastal Ace before USS Bainbridge, the mariners were rescued by USS Bainbridge at the request of the master of the M/T Kokuka Courageous,” the statement said.

The 23 crew members from the Front Altair are now being held in Iran, Fox News reported.

Iran was quick to show an image of what it says is the sailors in good health.

Iran’s English-language Press TV showed film and images and said they were in “full health.”

“This video refutes false reports by some media outlets claiming that Iran avoided help the sailors working on the vessel,” Press TV said. It said that of the 23 people in the crew 11 were Russian, 11 Filipino and one Georgian.

It is unclear when the sailors will leave Iran.

USS Mason, a guided-missile destroyer, is now patrolling the area of the Gulf of Oman where the attacks took place.

RELATED: US Navy Releases Footage of Tanker Attack Aftermath That Has ‘Iran Written All Over It,’ Trump Says

The U.S. has blamed Iran for the attacks and on Thursday, released video of what it said was an Iranian vessel removing an unexploded mine from the hull of the Kokuka Courageous.

“You saw the boat. It has Iran written all over it,” President Donald Trump said during an interview Friday on “Fox & Friends.”

“They didn’t want the evidence left behind. They don’t know that we have things that we can detect in the dark that work very well. We have that. It was them that did it,” he said.

Iran has denied any role in the attacks.

“Fire has been contained on both tankers … We have sent experts to evaluate whether the crew rescued by Iran can return to (one) tanker,” Allahmorad Afifipour, head of ports in the Iranian province of Hormozgan, said, according to Reuters.

Meanwhile late Thursday, Yutaka Katada, president of Kokuka Sangyo shipping company which owns the Kokuka Courageous, said he doubted a mine caused the damage to his vessel.

“Our crew said that the ship was attacked by a flying object,” he said according to The New York Times.

He stated that the holes in the ship’s hull were above its waterline.

“There is zero possibility that they were torpedoes,” he said.

We are committed to truth and accuracy in all of our journalism. Read our editorial standards. </s> WASHINGTON — In the hours before the attack on the two tankers in the Gulf of Oman on Thursday, the Iranians spotted a US drone flying overhead and launched a surface-to-air missile at the unmanned aircraft, a US official told CNN.

The missile missed the drone and fell into the water, the official said.

Prior to taking fire, the American MQ-9 Reaper drone observed Iranian vessels closing in on the tankers, the official added, though the source did not say whether the unmanned aircraft saw the boats conducting an actual attack.

Still, it is the first claim that the US has information of Iranian movements prior to the attack.

CNN has not seen any imagery from the US drones.

Iran has strenuously denied any involvement in the attack.

The same official also said in the days prior to the attack, a US Reaper drone was shot down in the Red Sea by what is believed to be an Iranian missile fired by Houthi rebels.

The Pentagon had tough words for Iran on Friday as the US continues to assert its claim that Tehran was responsible for the attack on the two oil tankers in international waters after releasing video footage its says shows an Iranian patrol boat removing an unexploded mine from one of the vessels’ hulls.

“We’re making sure that General McKenzie and the central command has the resources and the support that they need to conduct their missions,” acting Defense Secretary Patrick Shanahan said, adding that the US continues to work on building an international consensus that Iran was behind the attack.

The United Kingdom released a statement Friday saying it is “almost certain” that a branch of the Iranian military — the Islamic Revolutionary Guard Corps (IRGC) — attacked two tankers.

The IRGC is an elite wing of the Iranian military that was established in the aftermath of the country’s revolution in 1979. In April 2019, the US officially designated it as a foreign terrorist organization, a move which was rejected by authorities in Tehran.

No other state or non-state actor “could plausibly have been responsible,” the statement added.

Iran does not appear to be backing off and continues to engage in provocative behavior, according to a US official, who told CNN on Friday that Iranian small boats are preventing tug boats from towing away one of the damaged tankers.

But the owner of the Front Altair tanker has said they have “no information” and “no details” about any type of obstruction around its vessel since the time of the attack, Frontline spokesperson Pat Adamson told CNN Saturday.

President Donald Trump seems convinced that Tehran was responsible.

“Iran did do it and you know they did it because you saw the boat,” he said, appearing to refer to the images and video released by the Pentagon late Thursday.

In the video, a smaller boat is shown coming up to the side of the Japanese-owned tanker. An individual stands up on the bow of the boat and can be seen removing an object from the tanker’s hull. The US says that object is likely an unexploded mine.

A senior diplomatic source of a US ally told CNN Friday, “It is a virtual certainty Iran was behind this latest attack. The video now nails it.”

The source added that the goal of the response from the US government thus far is all about publicly exposing Iranian actions and intensifying maximum pressure.

After the United States withdrew from the Iran nuclear deal, it adopted a policy of maximum economic pressure and sent a carrier group to the region, the source said this “Iranian retaliation is designed to show they can disrupt, and push oil prices up.”

The Trump administration predicted that the pressure from the United States would bring Iran to the negotiating table, but European leaders disagreed, believing it would empower the hardliners, the source continued.

Iran has denied any involvement in the incident, with its foreign minister suggesting that the US was quick to make allegations “without a shred of evidence.”

The attack could provide more fodder for Iran hawks within the US administration, whose recent Iran saber-rattling has frustrated Trump. One of them, national security adviser John Bolton, announced last month that the Pentagon was deploying the USS Abraham Lincoln Carrier Strike Group and a bomber task force to the Middle East in response to a “number of troubling and escalatory indications and warnings” from Iran.

The two tankers — one carrying oil and the other transporting chemicals — were attacked near the strategically important Strait of Hormuz, a vital shipping route that has been the focal point of regional tensions for decades. Roughly 30% of the world’s sea-borne crude oil passes through the strategic choke point, making it a flashpoint for political and economic friction.

Jonathan Cohen, acting US ambassador to the United Nations, said Thursday that he echoed Pompeo’s comments in a private meeting of the UN Security Council, describing the attack as “another example of Iran’s destabilizing activities in the region.”

The Iranian mission to the UN rejected the US’ claim.

Alireza Miryousefi, a spokesman for the Iranian mission, tweeted a statement saying Iran “categorically rejects the US unfounded claim” that Iran is behind the attacks and “condemns it in the strongest possible terms.”

He added that Iran “expresses concern” over the “suspicious incidents.” And he called it “ironic” that the US, which withdrew from the nuclear deal with Iran, the Joint Comprehensive Plan of Action (JCPOA), is now calling Iran to come back for negotiations and diplomacy.

Speaking on Friday at a conference in Tajikistan, Iranian President Hassan Rouhani said his country was willing to further scale back its commitment to the JCPOA if it does not receive “the necessary response from other signatories.”

“We still believe that making good on commitments by all the signatories could have a major role in preserving regional and global peace and security. Iran will unilaterally not be able to remain as the party adhering to the JCPOA. Other parties need to do their own share as regards the deal,” he said.

This story and headline have been updated. </s> Two oil tankers near the strategic Strait of Hormuz were damaged in suspected attacks on Thursday, an assault that left one ablaze and adrift as sailors were evacuated from both vessels and the U.S. Navy rushed to assist amid heightened tensions between Washington and Tehran.

The Navy and the ship's owners offered no immediate explanation on what weapon caused the damage to the MT Front Altair and the Kokuka Courageous in the Gulf of Oman off the coast of Iran, though all believed the ships had been targeted in an attack.

It marks the latest mysterious incident to target the region's oil tankers. The U.S. alleged that Iran used limpet mines to attack four oil tankers off the nearby Emirati port of Fujairah last month. Iran has denied being involved, but it comes as Iranian-backed rebels in Yemen also have launched missile and drone attacks on Saudi Arabia.

Meanwhile in Iran, Supreme Leader Ayatollah Ali Khamenei warned that while Tehran doesn't seek nuclear weapons, "America could not do anything" to stop Iran if it did.

The comments came during a one-on-one meeting capping Japanese Prime Minister Shinzo Abe's high-stakes visit in Tehran that sought to ease Iran-U.S. tensions, suggested the efforts had failed.

Benchmark Brent crude spiked at one point by as much 4% in trading following the suspected attack, to over $62 a barrel, highlighting how crucial the area remains to global energy supplies. A third of all oil traded by sea passes through the strait, which is the narrow mouth of the Persian Gulf.

Cmdr. Joshua Frey, a 5th Fleet spokesman, said the U.S. Navy was assisting the two vessels that he described as being hit in a "reported attack." He did not say how the ships were attacked or who was suspected of being behind the assault.

Dryad Global, a maritime intelligence firm, preliminarily identified one of the vessels involved as the MT Front Altair, a Marshall Islands-flagged crude oil tanker. The vessel was "on fire and adrift," Dryad added. It did not offer a cause for the incident or mention the second ship.

The firm that operates the Front Altair told The Associated Press that an explosion was the cause of the fire onboard. International Tanker Management declined to comment further saying they are still investigating what caused the explosion. Its crew of 23 is safe after being evacuated by the nearby Hyundai Dubai vessel, it said.

The second vessel was identified as the Kokuka Courageous. BSM Ship Management said it sustained hull damage and 21 sailors had been evacuated, with one suffering minor injuries. Iranian state television said 44 sailors from the two tankers have been transferred to an Iranian port in the southern province of Hormozgan.

The timing of Thursday's suspected attack was especially sensitive as Abe's high-stakes diplomacy mission was underway in Iran. Japan's Trade Ministry said the two vessels had "Japan-related cargo."

On Wednesday, after talks with Iranian President Hassan Rouhani, Abe warned that any "accidental conflict" that could be sparked amid the heightened U.S.-Iran tensions must be avoided.

His message came just hours after Yemen's Iranian-backed Houthi rebels attacked a Saudi airport, striking its arrivals hall before dawn and wounding 26 people Wednesday.

A statement published by Khamenei's website after Abe's meeting Thursday with the supreme leader suggested a tense exchange between the two.

"We have no doubt about your good will and seriousness, but ... I don't regard Trump as deserving any exchange of messages," Khamenei reportedly told Abe.

Khamenei also said Iran remained opposed to building atomic weapons, but offered a challenge to Trump.

"You should know that if we planned to produce nuclear weapons, America could not do anything," said Khamenei, who has final say on all matters of state in Iran's Shiite theocracy.

In Tokyo, Japan's Chief Cabinet Secretary Yoshihide Suga, a top government spokesman, told reporters that Abe's trip was intended to help de-escalate Mideast tensions — not specifically mediate between Tehran and Washington. His remarks were apparently meant to downplay and lower expectations amid uncertain prospects for Abe's mission.

Tensions have escalated in the Mideast as Iran appears poised to break the 2015 nuclear deal with world powers, an accord that the Trump administration pulled out of last year.

Iran's nuclear deal, reached in 2015 by China, Russia, France, Germany, the United Kingdom and the U.S., saw Tehran agree to limit its enrichment of uranium in exchange for the lifting of crippling sanctions. Western powers feared Iran's atomic program could allow it to build nuclear weapons, although Iran long has insisted its program was for peaceful purposes.

In withdrawing from the deal last year, Trump pointed to the accord not limiting Iran's ballistic missile program and not addressing what American officials describe as Tehran's malign influence across the wider Middle East. Those who struck the deal at the time described it as a building block toward further negotiations with Iran, whose Islamic government has had a tense relationship with America since the 1979 takeover of the U.S. Embassy in Tehran and subsequent hostage crisis.

Already, Iran says it quadrupled its production of low-enriched uranium. Meanwhile, U.S. sanctions have cut off opportunities for Iran to trade its excess uranium and heavy water abroad, putting Tehran on course to violate terms of the nuclear deal regardless.

Aya Batrawy in Dubai, Mari Yamaguchi in Tokyo and Amir Vahdat in Tehran, Iran, contributed to this report </s> Washington (CNN) In the hours before the attack on the two tankers in the Gulf of Oman on Thursday, the Iranians spotted a US drone flying overhead and launched a surface-to-air missile at the unmanned aircraft, a US official told CNN.

The missile missed the drone and fell into the water, the official said.

Prior to taking fire, the American MQ-9 Reaper drone observed Iranian vessels closing in on the tankers, the official added, though the source did not say whether the unmanned aircraft saw the boats conducting an actual attack.

Still, it is the first claim that the US has information of Iranian movements prior to the attack.

CNN has not seen any imagery from the US drones.

Iran has strenuously denied any involvement in the attack.

The same official also said in the days prior to the attack, a US Reaper drone was shot down in the Red Sea by what is believed to be an Iranian missile fired by Houthi rebels.

The Pentagon had tough words for Iran on Friday as the US continues to assert its claim that Tehran was responsible for the attack on the two oil tankers in international waters after releasing video footage its says shows an Iranian patrol boat removing an unexploded mine from one of the vessels' hulls.

"We're making sure that General McKenzie and the central command has the resources and the support that they need to conduct their missions," acting Defense Secretary Patrick Shanahan said, adding that the US continues to work on building an international consensus that Iran was behind the attack.

Trump says Iran 'did do it'

The United Kingdom released a statement Friday saying it is "almost certain" that a branch of the Iranian military -- the Islamic Revolutionary Guard Corps (IRGC) -- attacked two tankers.

The IRGC is an elite wing of the Iranian military that was established in the aftermath of the country's revolution in 1979. In April 2019, the US officially designated it as a foreign terrorist organization, a move which was rejected by authorities in Tehran.

No other state or non-state actor "could plausibly have been responsible," the statement added.

Iran does not appear to be backing off and continues to engage in provocative behavior, according to a US official, who told CNN on Friday that Iranian small boats are preventing tug boats from towing away one of the damaged tankers.

But the owner of the Front Altair tanker has said they have "no information" and "no details" about any type of obstruction around its vessel since the time of the attack, Frontline spokesperson Pat Adamson told CNN Saturday.

President Donald Trump seems convinced that Tehran was responsible.

"Iran did do it and you know they did it because you saw the boat," he said, appearing to refer to the images and video released by the Pentagon late Thursday.

In the video , a smaller boat is shown coming up to the side of the Japanese-owned tanker. An individual stands up on the bow of the boat and can be seen removing an object from the tanker's hull. The US says that object is likely an unexploded mine.

A senior diplomatic source of a US ally told CNN Friday, "It is a virtual certainty Iran was behind this latest attack. The video now nails it."

The source added that the goal of the response from the US government thus far is all about publicly exposing Iranian actions and intensifying maximum pressure.

After the United States withdrew from the Iran nuclear deal, it adopted a policy of maximum economic pressure and sent a carrier group to the region, the source said this "Iranian retaliation is designed to show they can disrupt, and push oil prices up."

The Trump administration predicted that the pressure from the United States would bring Iran to the negotiating table, but European leaders disagreed, believing it would empower the hardliners, the source continued.

Iran denies involvement

Iran has denied any involvement in the incident, with its foreign minister suggesting that the US was quick to make allegations "without a shred of evidence."

The attack could provide more fodder for Iran hawks within the US administration, whose recent Iran saber-rattling has frustrated Trump. One of them, national security adviser John Bolton, announced last month that the Pentagon was deploying the USS Abraham Lincoln Carrier Strike Group and a bomber task force to the Middle East in response to a "number of troubling and escalatory indications and warnings" from Iran.

The two tankers -- one carrying oil and the other transporting chemicals -- were attacked near the strategically important Strait of Hormuz, a vital shipping route that has been the focal point of regional tensions for decades. Roughly 30% of the world's sea-borne crude oil passes through the strategic choke point, making it a flashpoint for political and economic friction.

Jonathan Cohen, acting US ambassador to the United Nations, said Thursday that he echoed Pompeo's comments in a private meeting of the UN Security Council, describing the attack as "another example of Iran's destabilizing activities in the region."

The Iranian mission to the UN rejected the US' claim.

Alireza Miryousefi, a spokesman for the Iranian mission, tweeted a statement saying Iran "categorically rejects the US unfounded claim" that Iran is behind the attacks and "condemns it in the strongest possible terms."

He added that Iran "expresses concern" over the "suspicious incidents." And he called it "ironic" that the US, which withdrew from the nuclear deal with Iran, the Joint Comprehensive Plan of Action (JCPOA), is now calling Iran to come back for negotiations and diplomacy.

Speaking on Friday at a conference in Tajikistan, Iranian President Hassan Rouhani said his country was willing to further scale back its commitment to the JCPOA if it does not receive "the necessary response from other signatories."

"We still believe that making good on commitments by all the signatories could have a major role in preserving regional and global peace and security. Iran will unilaterally not be able to remain as the party adhering to the JCPOA. Other parties need to do their own share as regards the deal," he said.

This story and headline have been updated. </s> What The U.S. Military Knows About The Attacks On Oil Tankers In The Gulf Of Oman

Before the two tankers were attacked Thursday there were four other ships attacked in the last month around the Persian Gulf. The U.S. Navy watches the sea lanes there closely.

These two tankers that were attacked yesterday in the Gulf of Oman weren't the only ones. Four other ships were attacked in the region in just the last month. The U.S. Navy watches the sea lanes there closely. NPR's Pentagon correspondent Tom Bowman has been reporting on what the military knows. He joins us now. And Tom, let's just talk about what you've learned so far starting with where those two tankers are now.

TOM BOWMAN, BYLINE: Well, Audie, I'm told one of the ships, the Japanese-owned Kokuka Courageous, is being towed by tugs. The fire is out on the vessel. Crew's back on board, and the destroyer USS Bainbridge is on overwatch. This second vessel, the Norwegian-owned Front Altair - tug operators are saying they've been told by Iranian fast boat operators not to move the ship according to U.S. military officials, and they say that's what the tug operators are telling their company officials in Oman.

CORNISH: What more is the U.S. saying about what happened?

BOWMAN: Well, U.S. military personnel are now inspecting this ship, the Courageous, and saying it appears an explosive device left a hole that folds in, meaning it was not an internal but rather an external explosion. They also say they're pulling off what appears to be a mine or two and seeing scorchers on the ship. We could see pictures of that.

And of course as we just learned, the president is saying Iran did it. The Pentagon released this video they say is an Iranian ship taking a limpet mine off one of the tankers. Iran denies any involvement. The foreign minister, Mohammad Zarif, said the U.S. has immediately jumped to make allegations against Iran without a shred of factual or circumstantial evidence.

CORNISH: In the meantime, are there plans to send any more U.S. ships to the area?

BOWMAN: Well, the Bainbridge is there, of course. And another destroyer, the USS Mason, which was off Karachi, Pakistan, is now off Oman. I'm told it's possible you could see other ships and aircraft heading there in the coming days. That's something that the top military officer for the region, General Frank McKenzie, was asking about even before these explosions.

CORNISH: Tom, I want to step back and look at some of the history here because some people may remember the so-called tanker wars of the 1980s. And at that time, as Iran and Iraq fought, they attacked ships, so then the U.S. began escorting some ships through those waters. Is that something we could see again?

BOWMAN: You know, we could see that again. And of course, Audie, during the tanker war, it got very complicated very quickly. The U.S. ended up firing on Iranian ships and shot down an Iranian airliner. And four years ago, there was a week-long escort effort after Iranian fast boats grabbed the crew of the container ship and brought them off Iran.

Now, this effort, I'm told, is - requires a good number of ships. And I was just talking with Ash Carter, the former defense secretary just yesterday. And he said, you know, it requires a lot of planning. And it's not something you do lightly.

CORNISH: Tom, before I let you go, do you get any sense that the Pentagon feels like they're on the defensive here in terms of explaining themselves?

BOWMAN: No, they think the evidence is pretty clear. But again, there's skepticism, as we heard in Europe. There's skepticism obviously from Iran. And they may offer Congress a little more detailed information maybe that they can't publicly release. And I'm thinking about, you know, radio intercepts from this ship maybe back to Iran if that's the case, if it was Iranian. And also, you can track these ships, of course. Did this ship come from an Iranian port? So there's a lot more they could provide, and I'm sure they have it. </s> The US military has released a video it said showed Iran’s Revolutionary Guard removing an unexploded limpet mine from one of the oil tankers targeted near the Strait of Hormuz.

The US Navy rushed to assist the stricken vessels in the Gulf of Oman off the coast of Iran, including one that was set ablaze on Thursday by an explosion.

The ships’ operators offered no immediate explanation on who or what caused the damage against the Norwegian-owned MT Front Altair and the Japanese-owned Kokuka Courageous.

Each was loaded with petroleum products, and the Front Altair burned for hours, sending up a column of thick black smoke.

Iran has denied being involved in the attack, calling it an “unfounded claim” in the US’s “Iranophobic campaign”.

However, Iran previously used mines against oil tankers in 1987 and 1988 in the Tanker War, when the US Navy escorted ships through the region.

The black-and-white footage, as well as still photographs released by the US military’s Central Command, appeared to show the limpet mine on the Kokuka Courageous.

A Revolutionary Guard patrol boat pulled alongside the ship and removed the mine, Central Command spokesman Captain Bill Urban said.

“The US and the international community stand ready to defend our interests, including the freedom of navigation,” Capt Urban said.

“The United States has no interest in engaging in a new conflict in the Middle East. However, we will defend our interests.”

Iran earlier denied involvement in a statement from its mission to the United Nations.

“The US economic war and terrorism against the Iranian people as well as its massive military presence in the region have been and continue to be the main sources of insecurity and instability in the wider Persian Gulf region and the most significant threat to its peace and security,” the statement said.

The suspected attacks occurred at dawn on Thursday about 25 miles off the southern coast of Iran.

The Front Altair, loaded with the flammable hydrocarbon mixture naphtha from the United Arab Emirates, radioed for help as it caught fire.

A short time later, the Kokuka Courageous, loaded with methanol from Saudi Arabia and Qatar, also called for help.

The US Navy sent a destroyer, the USS Bainbridge, to assist, said Commander Joshua Frey, a 5th Fleet spokesman. He described the ships as being hit in a “reported attack”.

Thursday’s attack resembled another in May that targeted four oil tankers off the nearby Emirati port of Fujairah.

US officials similarly accused Iran of targeting the ships with limpet mines, which are magnetic and attach to the hulls of a ship. The mines disable but do not sink a vessel.
A U.S. official says Iranian Navy gunboats are preventing the damaged Norwegian-owned Front Altair oil tanker from being towed away by two private tugboats in the Gulf of Oman.