Image caption Algerian troops ended the siege on Saturday 
 
 Five suspected members of the Islamist group which held foreign and local workers hostage at an Algerian gas plant have been arrested, reports say. 
 
 The reports came a day after the Algerian authorities said all 32 hostage-takers had been killed at the In Amenas gas installation. 
 
 At least 25 bodies were found at the complex on Sunday, reports say. 
 
 It is unclear whether they were captors or captives. Officials say a definitive death toll will be released later. 
 
 On Saturday officials said least 23 staff at the facility had died during the four-day siege, with some Western workers still unaccounted for. 
 
 The siege was ended in a raid by troops on Saturday. 
 
 Officials said the army launched its assault after Islamist militants began killing foreign hostages. 
 
 UK Prime Minister David Cameron and US President Barack Obama have blamed "terrorists" for the hostages' deaths. 
 
 We are ready to negotiate with the west and the Algerian government, provided they stop their bombing of Mali's Muslims Mokhtar Belmokhtar, Militant leader Profile: Mokhtar BelmokhtarTerror threat to last 'decades' - UK 
 
 And on Sunday French Defence Minister Jean-Yves Le Drian described the hostage-taking as an "act of war". 
 
 "What strikes me the most is that we're saying 'hostage-taking' but when there are so many people concerned, I think this is an act of war," he told French TV. 
 
 As Western leaders condemned the kidnappings, Algerian Energy Minister Youcef Yousfi said Algeria would boost security at its energy installations without outside help. 
 
 "It is out of the question to allow foreign security forces to handle the security of our oil facilities," he said, quoted by Algeria's APS news agency. 
 
 During a visit to the affected plant, Mr Yousfi said it would resume production within two days. 
 
 'Talks call' 
 
 "Five terrorists were found still alive this morning," said the private Ennahar TV channel, quoted by AFP news agency. 
 
 The agency said residents of the nearby town of In Amenas were staying indoors, amid rumours that the army operation to end the siege was not over. 
 
 Algerian Communications Minister Mohammed Said said earlier that the militants were from six different countries, "nationals of Arab and African countries, and of non-African countries". 
 
 Mr Said added that a final death toll would be released in the coming hours. 
 
 Mauritanian website Sahara Media says Mokhtar Belmokhtar, the suspected organiser of the siege, has claimed responsibility for it in a video message. 
 
 The four-day siege 16 January: Militants attack two buses carrying In Amenas workers, killing two 
 
 They then go on to the gas facility's living quarters and main installation, seizing hostages 
 
 Some gas workers manage to escape 
 
 17 January: Algerian forces attack after the militants try to move their hostages in five 4x4s - four of the vehicles are destroyed in an air strike and an unknown number of hostages killed 
 
 18 January: Stalemate as Algerian forces surround the gas plant where the remaining hostages are held 
 
 19 January: Algerian forces launch a final assault after reports that the hostage-takers were killing their captives 
 
 20 January: Algeria says death toll of 32 hostage-takers and at least 23 captives is likely to rise Q&A: Hostage crisis 
 
 The website said the video - recorded on 17 January while the siege was still going on but not posted on the website - showed the militant leader saying he was prepared to negotiate with Western and Algerian leaders if operations against Islamists in Mali were stopped. 
 
 Three Britons are confirmed dead, and a further three are missing, feared dead. 
 
 UK officials were "working hard" to locate the missing, said Foreign Secretary William Hague. 
 
 "Everything seems to indicate" that a Colombian citizen resident in the UK is among the dead, the Colombian president has said. 
 
 But he added that information about Carlos Estrada, who worked for BP, was "not 100%". 
 
 Japanese officials said they had no confirmation of the fate of 10 nationals who remained unaccounted for, despite reports that nine had died. 
 
 Foreign Ministry spokesman Yoshihide Suga said a government aircraft would be sent to bring home seven others who had survived. 
 
 You fear the worst, you can't put into words how bad you feel, it's something you never want to go through again Alan Wright, British hostage UK hostages speak of Algeria ordeal 
 
 Two Malaysians are unaccounted for, as are five Norwegians. 
 
 State news agency APS said 685 Algerian workers and 107 out of 132 foreigners working at the plant had been freed, citing interior ministry figures. 
 
 The nationalities of some of the hostages killed are still not known. 
 
 Well-planned assault 
 
 The crisis began on Wednesday when militants attacked two buses carrying foreign workers to the remote site in south-eastern Algeria. A Briton and an Algerian reportedly died in the incident. 
 
 The militants then took Algerians and expatriates hostage at the complex, which was quickly surrounded by the Algerian army. 
 
 A statement from the kidnappers said the assault on the gas plant was launched in retaliation for French intervention against Islamist groups in neighbouring Mali. 
 
 However, France only decided last week to intervene militarily in Mali. Analysts say the assault on the gas facility was well-planned and would have required advance research, as well as possibly inside help. 
 
 The leader of the hostage-takers was a veteran fighter from Niger, named as Abdul Rahman al-Nigeri by the Mauritanian news agency ANI, which had been in contact with the militants. ||||| Story highlights Two Americans unaccounted for, senior U.S. official says 
 
 Obama says "scourge of terrorism" must be fought 
 
 Algerian state news: At least 55 people, including hostages and militants, have died 
 
 The militants targeted an eastern Algerian gas facility where many foreigners workers 
 
 Algerian troops ended a hostage crisis at a remote gas facility Saturday with one last, bloody assault, Algerian and Western officials said, after three days of chaos and confusion left dozens dead and fanned fears of a new terror front in Africa. 
 
 At least 23 hostages and 32 "terrorists" were killed around the sprawling facility in eastern Algeria's desert, the Algerian interior ministry said Saturday. Some 685 Algerian workers and 107 foreigners have been freed, it said. 
 
 It is not clear just how many people are still unaccounted for. A senior U.S. official said two Americans were among that number. 
 
 The saga closed after a "final" assault, which itself contributed to the deaths of seven hostages and 11 militants, according to Algerian state media reports. 
 
 An Algerian Radio report did not specify the nationalities of those killed. CNN is unable to verify the state media figures on the deaths. 
 
 Afterward, Algeria's military continued to clear mines planted by militants, the official Algerian Press Service reported, citing the country's state-owned oil and gas company. 
 
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 "While the site is still dangerous and there may be explosives that will need to be dealt with, the terrorist incident is now over," said British Prime Minister David Cameron, citing his conversation with his Algerian counterpart. 
 
 The militant siege caught the world's attention as it ensnared citizens from several nations and dragged on for days. 
 
 Algerian authorities said they believe the attack was revenge for allowing France to use Algerian airspace for an offensive against Islamist militants in neighboring Mali. 
 
 Whatever the rationale, the scale and gore of the terror has stirred world leaders to press for action beyond Algeria, especially with Islamic extremists asserting themselves more and more in recent weeks. 
 
 "Let me be clear: There is no justification for taking innocent life in this way," Cameron said. "Our determination is stronger than ever to work with allies ... around the world to root out and defeat this terrorist scourge and those who encourage it." 
 
 British Foreign Secretary William Hague said Algerian authorities "certainly worked very hard to try to save the lives of people from other countries. I think it's actually too early to pass judgment on (the Algerian military operation)." 
 
 U.S. President Barack Obama said his administration would work with other countries to "combat the scourge of terrorism in the region, which has claimed too many innocent lives. This attack is another reminder of the threat posed by al Qaeda and other violent extremist groups in North Africa." 
 
 In a statement, Obama said the United States will work with Algeria to prevent future such incidents. 
 
 Crisis highlights pressure, potential on Algeria 
 
 Algerian special forces moved in because the terrorists wanted to flee for Mali -- apparently to pressure France and others who have recently intervened in that country -- Algerian state TV reported Saturday. 
 
 The Islamic extremists also planned to blow up the gas installation, a threat that initially prompted Algeria to halt its military operation. The location was rigged to explode, with mines planted throughout, according to the senior U.S. official. 
 
 Algeria's status as Africa's largest natural gas producer, and as a major supplier of the product to Europe, heightens its importance to other nations and businesses who want to invest there. Yet that interest is coupled with pressure to make sure foreign nationals, and their business ventures, are safe. 
 
 The targeted plant in In Amenas, which is just 50 kilometers (30 miles) west of the Libyan border, is run by Algeria's state oil company, in cooperation with foreign firms such as Norway's Statoil and Britain's BP. 
 
 Saturday's last push there follows another one two days earlier, which spurred criticism from some countries that Algeria had unnecessarily endangered hostages' lives. 
 
 British Defense Secretary Philip Hammond said Britain was still pressing the Algerian government for full details, while confirming the Saturday assault resulted in more deaths. He called the loss of life "appalling and unacceptable," laying blame solely on the terrorists. 
 
 Like Cameron, Norwegian foreign ministry spokesman Svein Michelsen confirmed that the Algerian military offensive was over, but did not offer further details. 
 
 Nations scramble to account for missing 
 
 The overall death toll could rise, Algerian state TV reports, as authorities are still combing the area. 
 
 Amid the uncertainty, individual nations are scrambling to find out what happened to their citizens. It is not clear how many hostages were seized by the Islamist militants in the first place. 
 
 Five Norwegians are missing while "eight are now safe," Norwegian Prime Minister Jens Stoltenberg said. 
 
 Five British nationals and one UK resident are missing or feared dead in Algeria, Hague told reporters. This is in addition to one Briton, whose death was previously announced. 
 
 Colombia's president said a citizen was presumed dead. 
 
 The Scottish government said eight of its residents are safe. 
 
 There are no known French hostages unaccounted for, a Defense Minister Jean-Yves Le Drian said Saturday. 
 
 Three French nationals who were at the site are safe, the foreign ministry has said. 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 well-treated. 
 
 Of the BP employees, 14 are safe, and four BP employees are still missing in Algeria, BP Chief Executive Bob Dudley said. 
 
 At least one American, identified as Frederick Buttaccio, is among the dead, U.S. State Department spokeswoman Victoria Nuland said. The senior U.S. official told CNN that six freed Americans left Algeria and one remained. 
 
 One Romanian lost his life, a spokeswoman for the Romanian Ministry of Foreign Affairs told CNN on Saturday. Four other Romanians were freed. 
 
 And there are 14 Japanese unaccounted for, Chief Cabinet Secretary Yoshihide Suga said. 
 
 Malaysia's state-run news agency reported Thursday that two of its citizens were held captive. 
 
 Dramatic tales of escape from terror 
 
 When the crisis began Wednesday, militants gathered the Westerners into a group and tied them up, survivors said. The kidnappers wielded AK-47 rifles and put explosive-laden vests on some hostages, according to a U.S. State Department official. 
 
 Some survivors described their harrowing escapes by rigging up disguises, sneaking to safety with locals, and in at least one case, running for his life with plastic explosives strapped around his neck. 
 
 That man was Stephen McFaul, who -- according to his brother Brian -- was among a group of hostages who had been blindfolded, gagged and then packed into five Jeeps on Thursday, during Algerian forces' first offensive. 
 
 An explosion "wiped out" four of the vehicles, while McFaul's vehicle crashed. He was able to get out and, eventually, contact his family. 
 
 "I haven't seen my mother move as fast in all my life, and my mother smile as much, hugging each other," Brian McFaul of Belfast, Northern Ireland, said upon his family hearing his brother was safe. "... You couldn't describe the feeling." 
 
 Al Qaeda-linked group offered prisoner-hostage exchange 
 
 A spokesman for Moktar Belmoktar , a longtime jihadist who leads the Brigade of the Masked Ones -- a militant group associated with al Qaeda in the Islamic Maghreb -- reportedly offered to free U.S. hostages in exchange for two prisoners. 
 
 Behind the group claiming responsibility for the attack and kidnappings, he is known for seizing hostages and has long been targeted by French counterterrorism forces. 
 
 The prisoners are Sheikh Omar Abdel Rahman, who orchestrated the 1993 World Trade Center bombing, and Aafia Siddiqui , a Pakistani woman jailed in the United States on terrorism charges, the spokesman said in an interview with a private Mauritanian news agency. 
 
 Nuland rejected the offer, restating U.S. policy of not negotiating with terrorists.
– The Algerian hostage standoff appears to be over after four days, but the end came with more bloodshed: The government says kidnappers executed seven hostages during this morning's "final assault." That brings the death toll to at least 32 "terrorists" and 23 hostages, including one American, report AP and CNN. No details are out yet on nationalities of the latest victims. "In principle, it's over," a government official tells the New York Times. Only a "clean-up process" remains. A Turkish official says two remaining American hostages were found "safe and sound." Algeria's state news agency reports that another 11 of the al-Qaeda-linked militants were killed in the raid, but it did not say whether any remained alive. As for that "clean-up process": The militants reportedly booby-trapped the entire gas refinery with explosives, and Algerian troops had begun the painstaking task of clearing them.