New York (CNN) A suspicious package addressed to actor-director Robert De Niro was reported early Thursday at the Manhattan building where his production company is based, and its marking and contents appear similar to pipe bomb packages recently mailed nationwide to top Democrats, two law enforcement sources said. 
 
 Also Thursday, two suspicious packages addressed to former Vice President Joe Biden were found in Delaware , law enforcement officials said. 
 
 A photo of the package sent to Robert DeNiro, provided by a law enforcement official. 
 
 With Thursday's discoveries, at least 10 suspicious packages, all similar in appearance, have been found this week addressed to eight people who are prominent Democrats or high-profile critics of Donald Trump. 
 
 The package addressed to De Niro, found on the seventh floor of 375 Greenwich St. in New York City's Tribeca neighborhood, was reported to police around 4:45 a.m. 
 
 The building contains Tribeca Enterprises -- which includes De Niro's Tribeca Productions film and television company and organizes the Tribeca Film Festival -- and De Niro's Tribeca Grill restaurant 
 
 The package was received in the building's general mailroom on Wednesday, according to a law enforcement official. A retired police officer discovered the package, but initially didn't think anything of it and left it in his office. 
 
 After watching news reports, he recognized similarities between the package he had seen and the others sent to top Democrats and CNN, the official said. He called police early Thursday morning to inform them about it. 
 
 Police have sent the package to a secure facility in the Bronx, New York Police Department Commissioner James O'Neill said on Twitter 
 
 "The most highly trained experts in the world are investigating today's suspicious package in #TriBeCa," O'Neill's tweet reads. 
 
 X-ray images show that the package addressed to De Niro contains a device similar to the pipe bombs found in other packages this week that were addressed to prominent Democrats, the two sources said. 
 
 De Niro is a vocal critic of Trump. 
 
 JUST WATCHED Bombs sent to politicians in 'act of terror' Replay More Videos ... MUST WATCH Bombs sent to politicians in 'act of terror' 02:33 
 
 The package sent to the actor also had the same return address as the others: that of Democratic US Rep. Debbie Wasserman Schultz of Florida, the sources said. There is no information to suggest she sent the packages. 
 
 And, just as the other packages, the one sent to De Niro had six American-flag stamps arrayed in two rows. No postmark is visible on the front of the De Niro package, similar to some of the others, the sources said. 
 
 None of the bombs in the other packages detonated, and no one was injured. 
 
 JUST WATCHED X-ray of package reveals new info Replay More Videos ... MUST WATCH X-ray of package reveals new info 01:32 
 
 Before the De Niro and Biden packages were in police custody Thursday, authorities said seven pipe bombs stashed in manila envelopes were discovered this week addressed to six prominent Trump critics: Former President Barack Obama; former Secretary of State Hillary Clinton; former Attorney General Eric Holder; Democratic US Rep. Maxine Waters (one to her California office and one to her office in Washington); former CIA director John Brennan (sent to CNN's New York offices); and billionaire investor and Democratic donor George Soros. 
 
 Most of those devices showed the presence of a sulfur substance , which could have exploded, a law enforcement official said. 
 
 Those devices are believed to be pipe bombs, inherently unstable, and at risk of being set off just by handling. 
 
 Authorities already were aware at least one Biden package by Wednesday; it had been misaddressed and returned to sender, and postal officials were trying to track it down, two law enforcement sources said. 
 
 This photo of the package addressed to Biden was obtained by WTFX-TV in Philadelphia. 
 
 Details about how authorities ultimately found the two Biden packages on Thursday morning in Delaware weren't immediately available. But Delaware authorities have said investigators have responded to post offices in Wilmington and New Castle. 
 
 The FBI said Thursday that the package addressed to De Niro and the two addressed to Biden were "similar in appearance to the others." 
 
 The #FBI has confirmed three additional packages, similar in appearance to the others -- one in New York addressed to Robert DeNiro, and two in Delaware addressed to former Vice President Joseph Biden. — FBI (@FBI) October 25, 2018 
 
 Building is open after evacuation 
 
 Tribeca Enterprises co-founder Jane Rosenthal said Thursday that the building was evacuated after the package was found, but that it has been re-opened. 
 
 "The building is open and everybody is safe," she told CNN. "This is not what free speech should look like." 
 
 A police officer blocks off an area in Manhattan Thursday morning after a suspicious package addressed to Robert De Niro was reported at the Tribeca Enterprises building. 
 
 De Niro's criticism of Trump 
 
 At June's Tony Awards, De Niro went off-script while introducing a performance by Bruce Springsteen to curse Trump. 
 
 "First, I wanna say, 'f**k Trump,'" De Niro said. "It's no longer 'Down with Trump,' it's 'f**k Trump.'" 
 
 Trump responded to the comments in a series of tweets, calling De Niro "a very low IQ individual." 
 
 JUST WATCHED De Niro apologizes to Canada for Trump Replay More Videos ... MUST WATCH De Niro apologizes to Canada for Trump 00:46 
 
 It wasn't the first time De Niro had spoken out against the President. 
 
 In January, his speech at the National Board of Review Annual Awards Gala included a profanity-laced rant directed at Trump. 
 
 "Our baby-in-chief -- the j***-off-in-chief, I call him -- has put the press under siege, ridiculing it and trying to discredit it through outrageous attacks and lies," De Niro said. ""This f***ing idiot is the President. It's 'The Emperor's New Clothes' -- the guy is a f***ing fool ... our baby-in-chief -- the 'J******-in-chief' I call him." ||||| [Latest: two more devices were intercepted, one addressed to Senator Cory Booker and the other to James R. Clapper Jr., the former senior intelligence official.] 
 
 Federal authorities investigating a spate of pipe bombs sent this week to several prominent critics of President Trump have turned their attention to southern Florida, believing that a number of the devices were mailed from there, two people briefed on the matter said Thursday. 
 
 The focus on Florida came as three more devices were found, the F.B.I. said. Two were addressed to former Vice President Joseph R. Biden Jr. in Delaware and a third to the actor Robert De Niro, who lives and works in Lower Manhattan. 
 
 All 10 of the similar-looking packages discovered since Monday bore return addresses from Representative Debbie Wasserman Schultz, a Democrat whose district is in southern Florida. And Kirstjen Nielsen, secretary of the Department of Homeland Security, told Fox News on Thursday that some of the packages were sent from within the state. ||||| Packages addressed to Hillary Clinton, former President Obama, billionaire George Soros, ex-Attorney General Eric Holder, former CIA director John Brennan, Rep. Maxine Waters - who was sent two -- Joe Biden and Robert de Niro all appear to have the same characteristics. NBC has team coverage. 
 
 UPDATE: Some Devices Flawed, Unable to Explode; Others Yet to Be Analyzed, Several Investigators Say 
 
 Investigators seized three more suspected package explosives -- two addressed to former Vice President Joe Biden in Delaware and one addressed to Robert De Niro in New York -- early Thursday, bringing the total number of confiscated devices sent to high-profile Democrats and others to 10 in 72 hours. 
 
 Multiple officials briefed on the investigation say there are no solid leads on a suspect as of Thursday afternoon. While there are no known devices still outstanding, they remain concerned there could be others still undiscovered. 
 
 13 Suspicious Package Incidents Within five days, apparent explosive devices were detected in the mail addressed to Democratic politicians Barack Obama, Joe Biden, Hillary Clinton, Sen. Corey Booker and Rep. Maxine Waters; billionaire philanthropist George Soros; the New York City offices of CNN and others. No one was hurt and investigators are working to determine if the incidents are all linked, though many of the devices appeared similar. 
 
 Officials say they are looking into whether at least some of the packages were mailed from Florida. They also say the devices were poorly made and it is unclear if these were attempted hoaxes or simply a case of bad construction. 
 
 Ten have been seized in total since Monday, though most of the intercepts came Wednesday. Three more -- to Biden and De Niro -- came Thursday. News of the De Niro device broke first. That one was addressed to him and had been sent to a Greenwich Street building he owns that houses offices for Tribeca Films and Tribeca Grill. A building worker called police early Thursday because, after seeing Wednesday's news, he remembered seeing a similar package a day or so earlier. The device was safely removed from the property. 
 
 Less than two hours later, the FBI and local police swarmed a postal facility in Delaware in connection with the bombing investigation. Sources had said authorities suspected a similar device may have been addressed to Biden. Nothing was found at his house, but investigators apparently tracked it down in a New Castle postal facility, officials said. It was said to be akin to the others. About an hour later, a second package addressed to Biden was confiscated at a postal facility in Wilmington, Delaware. Details on that one weren't clear. 
 
 The De Niro device and at least the first Biden package had the same stamps and return address (that of Florida congresswoman and ex-Democratic National Committee chairman Debbie Wasserman Schultz) as others reported on Wednesday. 
 
 Two senior law enforcement officials say they are looking into whether some of the packages were mailed from Florida. They are also looking into any past incidents involving Wasserman Schultz's office and if any of those incidents could be connected to these devices. 
 
 As of early Thursday, there have been 10 such packages. In addition to Biden and De Niro, two devices in separate packages were addressed to Rep. Maxine Waters of California; ones were also addressed to Hillary Clinton, former President Obama, ex-Attorney General Eric Holder and former CIA director John Brennan. The first in the series was a mailbox pipe bomb left at the Westchester County home of billionaire philanthropist George Soros. 
 
 None of the devices detonated and no one has been hurt. Authorities are examining the crude explosives and warning there could be more out there. NBC News obtained an X-ray photo of one of the bombs, which shows protruding wires that appeared to be connected to a cylindrical device. 
 
 According to sources, the explosive devices were made from PVC pipe and contained a timer (likely a digital alarm clock) to set off the detonator. The powder contained in the bombs comes from pyrotechnics. X-rays show there was likely shrapnel inside the PVC pipe, law enforcement officials say. 
 
 Meanwhile, investigators examining the explosive devices are working to glean forensic clues to help identify who sent them, gathering fingerprints and DNA evidence while tracking the origin of the packages and the components used. While some have made note of the fact that the devices were not postmarked, multiple officials have said this was not uncommon, and that because of the soft packaging they could not go through automated sorting machines to have their postage canceled. 
 
 Former NYPD Commissioner Bill Bratton said on MSNBC Thursday that it's a plus the FBI has recovered so many of the package bombs. They will look into whether they were intended to function, how they were supposed to detonate and where the design came from. That could help find an online trail. 
 
 Larry Johnson, a former head of criminal investigations for the U.S. Secret Service who also served as a special agent in charge of the presidential protective detail, said it is highly likely that the person or people who built the bombs have been previously flagged by law enforcement. 
 
 If you have info that could assist the #FBI's investigation of suspicious packages, call 1-800-CALLFBI (225-5324) or use http://tips.fbi.gov. 
 
 The reaction to the devices was swift and visceral, with high-level people on both sides of the aisle, including the president, pledging Wednesday no resources would be spared in taking down whoever was responsible. 
 
 The tone became more partisan-charged over the course of the day, with some assailing the White House for its "violent political rhetoric." Upon news three more packages, including two addressed to Biden, were seized early Thursday, Brennan, who was the addressee on the CNN package, tweeted at Trump to "Look in the mirror" and "Clean up your act." 
 
 "Stop blaming others," Brennan tweeted. "Your inflammatory rhetoric, insults, lies & encouragement of physical violence are disgraceful." 
 
 The president responded shortly thereafter, slamming "Fake News" as "a very big part of the Anger we see today in our society." 
 
 "Mainstream Media must clean up its act, FAST," Trump added. 
 
 Top News: Friends, Family Say Goodbye to Bar Shooting Victim ||||| A very big part of the Anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media that I refer to as Fake News. It has gotten so bad and hateful that it is beyond description. Mainstream Media must clean up its act, FAST!
– It looks like we can add Joe Biden and Robert De Niro to the list of targets of the person or persons who have been sending pipe bombs to prominent Democrats after more suspicious devices were intercepted Thursday. That brings the count to at least nine devices so far since Monday, reports the New York Times. The latest developments: De Niro: Law enforcement sources tell CNN that a suspicious package sent to a Manhattan building that houses De Niro's Tribeca Grill restaurant and his production company's office matches the pipe bomb packages intercepted this week. An official tells NBC that a worker at the building in the Tribeca neighborhood called police at around 4am after seeing news reports and recalling having spotted the package a day or two ago. De Niro is a prominent critic of President Trump. Biden: NBC News reports that authorities in Delaware found two devices addressed to the former vice president, one at a postal facility in New Castle and the other at a postal facility in Wilmington. Blame game: President Trump on Thursday again blamed the media for the current political climate. "A very big part of the Anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media that I refer to as Fake News," he tweeted Thursday. "It has gotten so bad and hateful that it is beyond description. Mainstream Media must clean up its act, FAST!"