TASK DEFINITION: In this task, you are given news articles and you need to generate a highlight, i.e., a short summary, with a maximum length of 10 lines.
PROBLEM: (CNN) -- The hostage crisis in eastern Algeria is over, but the questions remain. Among them, exactly how many people are unaccounted for at a remote natural gas facility after three days of chaos that ended Saturday, leaving at least 23 hostages and dozens of Islamist militants dead. Some 685 Algerian workers and 107 foreigners were freed, the Algerian Interior Ministry said. Britain's BP said Sunday four of its workers remain unaccounted for. And Norway's Statoil said five of its employees were missing, while 12 others are now home in Norway, Algeria and Canada. "Search efforts are ongoing at the gas installation, looking for more possible victims. I fear the numbers will be updated with more victims later today when the search operation is expected to end," said Mohammed Said, Algeria's communication minister. The attackers came from six countries -- only three were Algerian -- and included Arabs and Africans, Said told state-run Radio Algeria. Algeria's military found numerous "foreign military uniforms" in its sweep of the In Amenas facility, its Interior Ministry said. Mauritania's Sahara Media news agency said Sunday it had a video from Moktar Belmoktar, who leads the Al-Mulathameen Brigade associated with al Qaeda in the Islamic Maghreb that regional media have reported was behind the attack. In it, Belmoktar said, "We at al Qaeda are claiming responsibility of this blessed guerrilla operation." Belmoktar has communicated with this and other news sites before, said Andrew Lebovich, a Senegal-based security analyst. But the news agency did not post the video, and CNN has not independently confirmed its authenticity. Eleven former hostages -- among them British citizens -- have gotten medical treatment and psychological counseling from the U.S. military at a U.S. naval base in Sigonella, Italy, a U.S. official said Sunday. The hostages were brought from Algeria to the base Friday, the official said, and are being flown to their home countries as their conditions warrant. The remains of one American hostage were also brought to the base, the official said. In a statement Saturday night, the White House said it was in close contact with Algeria's government to "gain a fuller understanding of what took place." British Foreign Secretary William Hague echoed those remarks, adding his government is "working hard to get definitive information" about each individual. Japan has 10 citizens -- likely affiliated with JGC Corp., an engineering firm that was involved in gas production in In Amenas -- who are yet to be confirmed safe, in addition to a number of dead. Opinion: Algeria crisis is a wakeup call for America . Such Islamist militant activity is not new to Africa, including recent violence in Mali and Somalia. Algeria's status as Africa's largest natural gas producer and a major supplier of the product to Europe heightens its importance to those who want to invest there. Yet that interest is coupled with pressure to make sure foreign nationals, and their business ventures, are safe. Youcef Yousfi, Algeria's energy and mining minister, insisted Sunday his country can keep its gas facilities secure and ruled out foreign forces coming in to help. "We are going to strengthen security, and we rely first on our means and resources," Yousfi said, according to the official Algerian Press Service. Raids turn deadly . Militants in pickup trucks struck the sprawling gas complex about 50 kilometers (30 miles) west of the Libyan border at dawn Wednesday, gathered the Westerners who worked there into a group and tied them up. The In Amenas plant is run by Algeria's state oil company, in cooperation with foreign firms such as Statoil and BP, and because of that employed workers from several countries. The kidnappers wielded AK-47 rifles and put explosive-laden vests on some hostages, according to a U.S. State Department official. Algeria said the attack was in retaliation for allowing France to use Algerian airspace for an offensive against Islamist militants in neighboring Mali. And Sahara News' report Sunday claimed Belmoktar said "40 immigrant Jihadists and supporters of Muslim countries" led the siege in retaliation for the Mali offensive. Read more: Mali takes key town as nations ready more troops . But regional analysts believe it was too sophisticated to have been planned in just days. On Thursday, Algerian special forces moved in because the government said the militants wanted to flee to Mali. The Islamic extremists also planned to blow up the gas installation and rigged it with mines throughout, the U.S. official said. Thursday's military incursion succeeded in freeing some hostages -- but not all. Some survivors described their harrowing escapes by rigging up disguises and sneaking to safety with locals, with at least one survivor running for his life with plastic explosives strapped around his neck. Several hostages died. And the Algerian military came under criticism from some quarters for unnecessarily endangering hostages' lives. Undeterred, the government followed with a second push Saturday. That assault killed the remaining hostage-takers but resulted in more hostage deaths. The army intervened "to avoid a bloody turning point of events in this extremely dangerous situation," the Algerian Interior Ministry said Saturday. "It was clear that the terrorists were determined to escape the country with the captives and to bomb the gas installations." On Sunday, an American lawmaker said the Algerian government turned down U.S. offers to help during the crisis. "They decided they were going to handle it their way," said Rep. Mike Rogers, a Michigan Republican who is chairman of the U.S. House Intelligence Committee. "They did not want us or the other hostage nations involved in the decision-making." British Defense Secretary Philip Hammond called the loss of life "appalling and unacceptable," while laying blame solely on the terrorists. Countries mourn dead, try to track down missing . While the military part of the operation is over, the searching and mourning is not for people in countries worldwide. In addition to combing the sprawling desert site, Algerian forces are searching hospitals and medical centers around the country, as well as towns and villages near the targeted site, according to a statement Sunday from Statoil. 'Mr. Marlboro': The veteran jihadist behind the attack in Algeria . Colombia . Colombia's president said a citizen was presumed dead. France . No known French hostages are unaccounted for, France's Defense Ministry said Saturday. One man -- identified as Yann Desjeux -- died after telling the French newspaper Sud Ouest on Thursday that he and 34 other hostages of nine different nationalities were treated well. Three others who had been held are safe. Japan . There are still 10 Japanese who have yet to be confirmed safe, JGC -- the engineering firm -- said Sunday. Malaysia . Three hostages were on their way back to Malaysia, the country's state-run news agency reported Sunday. But there is a "worrying possibility" that another is dead, while a fifth is unaccounted for, the agency said. Norway . Five Norwegians are missing, while eight are safe, Norwegian Prime Minister Jens Stoltenberg said. "We know that there are many fatalities," Statoil CEO Helge Lund said Sunday. "A new day without answers has increased our concern." Romania . One Romanian lost his life, the country's Foreign Ministry said Saturday. Four other Romanians were freed. United Kingdom . Three British citizens were killed, the Foreign Office said Sunday. Three other British nationals and a UK resident are also "believed dead," he said. Twenty-two other Britons who were taken hostage have safely returned home. United States . At least one American, identified as Frederick Buttaccio, is among the dead, the State Department said. Six freed Americans left Algeria and one remained. Read more: Algeria attack may have link to Libya camps . CNN's Paul Cruickshank, Slma Shelbayah, Kevin Bohn, Barbara Starr and Per Nyberg contributed to this report.

SOLUTION: NEW: An Algerian official says Algeria doesn't need help securing its energy facilities .
NEW: Algerians are searching hospitals, villages and more for missing, Statoil reports .
The number of those killed in the crisis will likely go up, an Algerian official says .
A new video reportedly claims responsibility in the name of al Qaeda .

PROBLEM: Seoul, South Korea (CNN) -- South Korea will conduct naval fire drills near a flashpoint with the North that resulted in the deaths of four people, military officials said Thursday. The South Korean Joint Chiefs of Staff announced the exercises will take place in the seas southwest of Yeonpyeong Island on a day to be announced between December 18 and 21. The South previously announced military exercises for this week, but Thursday's announcement adds to them. Tensions mounted between the Koreas on November 23, when North Korea shelled the island, which lies in South Korean territory. The attacked killed two marines and two civilians and injured 18 people. Last month's attack was the first direct artillery assault on South Korea since 1953, when an armistice ended fighting. The North has accused the South of provoking the attack because shells from a South Korean military drill landed in the North's waters. North Korea Thursday accused the South's new defense minister, Kim Kwan-jin, of "going reckless like a puppy knowing no fear of a tiger," state-run KCNA reported. During his confirmation hearing this month, Kim said South Korea would respond with airstrikes if the North attacks it again. The South Korean joint chiefs said the drills will be carried out in the presence of officials from the Military Armistice Committee and representatives from U.N. party members to ensure that the exercise is lawful and follows rules of the armistice.

SOLUTION: New drills add to military exercises around the Korean peninsula .
North Korea shells a South Korean island last month .
The drills will take place near a flashpoint that left four people dead .

PROBLEM: Washington (CNN) -- The much-maligned, color-coded Homeland Security Advisory System is about to be consigned to the proverbial dustbin of history. Not that anyone is really paying attention. Homeland Security Secretary Janet Napolitano is expected to announce Thursday that the almost 9-year-old threat alert system will go away in April. It will be replaced by the new National Terror Advisory System that will focus on specific threats in geographical areas, a department source said Wednesday. The source did not provide details of the new system, which Napolitano will unveil at what the department is calling "the first annual 'State of America's Homeland Security' address" at George Washington University. The top Democrat and Republican on the House Homeland Security Commission reacted positively to the news, although committee chairman Rep. Peter King, R-New York, reserved judgment on the specifics. "Though the system served a valuable purpose in the terrible days and months following the terrorist attacks of September 11, it was clearly time for the current color-coded system to be replaced with a more targeted system," King said. "I know they have been working on this for a long time. It sounds to me like the changes they are proposing make sense. We will have to wait and see how they implement this new, more targeted system. I expect the biggest challenge for DHS will be balancing the need to provide useful and timely information with the need to protect sensitive information." "The old color coded system taught Americans to be scared, not prepared," said ranking member Rep. Bennie Thompson, D-Mississippi. "Each and every time the threat level was raised, very rarely did the public know the reason, how to proceed, or for how long to be on alert. I have raised concerns for years about the effectiveness of the system and have cited the need for improvements and transparency. Many in Congress felt the system was being used as a political scare tactic -- raising and lowering the threat levels when it best suited the Bush administration." President George W. Bush established the Homeland Security Advisory System by presidential directive on March 11, 2002, just a few months after the 9/11 terrorist attacks in New York and Washington. The five levels -- green for low, blue for guarded, yellow for elevated, orange for high and red for severe -- were intended to identify the risk of terrorist attack. The initial level was yellow, which the system retained until September 11, 2002, when it was raised to orange to cover the first anniversary of the attacks. It was lowered back to yellow on September 24. In its lifetime, the threat level has been raised to orange/high five times, although it went to that level three other times for specific industries. The threat level was raised to red/severe once -- on August 10, 2006, and only for commercial flights from the United Kingdom to the United States -- when British authorities announced they had disrupted a major plot to blow up aircraft. The level went down to orange on August 16, 2006, where it remains. The general threat level is yellow/elevated. The two lower levels have never been used, and task force looking at the system recommended in 2009 eliminating them altogether and making yellow the lowest threat level but renaming it "guarded." Almost from the start, the threat level system was the butt of jokes and multiple parodies. The "Democracy Threat Advisory Level" went from green/low ("Wow, clean money systems really work") to red/severe ("Martial law, but it's for your own good"). A "Total Headcase Advisory System" began with "George Soros is arrested" and ended with "Hillary Clinton is elected president." Still another announced that Homeland Security and Crayola had jointly revised the system, changing green to aquamarine, blue to raw umber, yellow to burnt sienna, orange to neon carrot and red to cotton candy. The public didn't care much for the system either, with polls conducted at the time indicating most Americans found it confusing and not very useful. More seriously, however, some critics accused the Bush administration of using using the system to generate fear at politically sensitive times, such as just before the 2004 election. And just days after his 2005 resignation, then-Homeland Security Secretary Tom Ridge told a Washington forum that he sometimes disagreed with the rationale for raising the alert but was overruled by others on the Homeland Security Advisory Council, which made the decisions. The council included Attorney General John Ashcroft, FBI chief Robert Mueller, CIA director George Tenet, Defense Secretary Donald Rumsfeld and Secretary of State Colin Powell. "More often than not we (the department) were the least inclined to raise it," Ridge told reporters after the forum. "Sometimes we disagreed with the intelligence assessment. Sometimes we thought even if the intelligence was good, you don't necessarily put the country on (alert). ... There were times when some people were really aggressive about raising it, and we said, 'For that?' " And in 2009, Ridge wrote in a tell-all book that sometimes officials such as Ashcroft and Rumsfeld pressured the department to change the level, describing a 2004 event in which his arguments against raising the alert worked. "I believe our strong interventions had pulled the 'go-up' advocates back from the brink. But I consider the episode to be not only a dramatic moment in Washington's recent history, but another illustration of the intersection of politics, fear, credibility and security," he wrote. "After that episode, I knew I had to follow through with my plans to leave the federal government," he wrote. Ridge announced his resignation on November 30, 2004, and left office on February 1, 2005. The Bush administration denied Ridge's assertions, however. "Nobody's more surprised than I am," then-Homeland Security adviser Fran Townsend told CNN's Wolf Blitzer. "Of course, Tom Ridge never expressed those concerns while he was in the administration, nor did he when I spoke to him after he left ... (He) wasn't the only one in that meeting who suggested the terror alert shouldn't be raised. At no time was there a discussion of politics in that meeting. And the president was made a consensus recommendation from the council that he accepted -- not to raise the terror alert." Townsend is now a national security contributor for CNN. CNN's Fran Townsend contributed to this report .

SOLUTION:
Homeland Security Secretary Janet Napolitano will make official announcement Thursday .
The new system will focus on specific threats in geographical areas, a source says .
The current color-coded system was established in 2002 in wake of 9/11 attacks .
The system was often criticized as confusing by public and parodied by comics .