The death toll at a gas plant deep in Algeria's Sahara desert rose to 80 on Sunday, with one Western leader warning of a long war on terror ahead in North Africa following one of the worst hostage crisis in recent years, DPA reported.
The nationalities of all the victims was not clear, and the Algerian government warned the toll could rise even further at the plant, where staff from more than 10 nations worked.
"I am afraid that the army troops now carrying out a large search operation inside the factory will find more victims," Telecom Minister Mohammed al-Said said on state radio.
Algerian officials had earlier said 23 hostages and 32 terrorists had died during the standoff, in which Algerian forces using combat helicopters attacked the militants and surrounded the complex.
The extremists, linked to al-Qaeda in the Islamic Maghreb, had began their attack on Wednesday, using machine guns, missile launchers, rifles, rockets, mortars and grenades.
They claimed they staged their attack because France last week launched a military operation in neighbouring Mali against Islamist militants controlling much of the north.
Their leader, veteran militant Mukhtar Belmukhtar, had demanded and end to the Mali operation in a videotape dated January 17 and made public on Sunday, the Mauritanian website Sahara Media reported.
"We are ready to negotiate with the Western countries and the Algerian regime on condition the aggression and bombing against the Muslim people of Mali stop," he was quoted as saying.
"We in al-Qaeda announce our responsibility for this blessed courageous operation," he said of the hostage taking.
British Prime Minister David Cameron, who said three Brits were confirmed dead and three feared dead, warned of a "global response" that would last "years, even decades."
Britain would use its chairmanship of the G8 group of wealthy nations to push against the "extremist, Islamist, al Qaida-linked terrorist group," said Cameron.
He also warned: "Just as we had to deal with that in Pakistan and in Afghanistan, so the world needs to come together to deal with this threat in North Africa."
In total, 685 Algerians and 107 foreigners escaped or were freed from the plant, which is run by BP, Norway's Statoil and Algeria's state oil firm and located 1,300 kilometres southeast of Algiers.
Al-Said said the dead militants included three Algerians and foreigners from at least six countries. "They belong to Arab, African and non-African countries," he said.
The Al Shorouk newspaper, citing security sources, said the militants included 11 Tunisians, seven Egyptians, five Malians, three Algerians, two Canadians, a Nigerian and a Mauritanian.
The breakdown was based on confessions from two militants captured during the military raids, the independent paper said.
Reports have said nationals of Austria, Britain, Colombia, France, Ireland, Japan, Kenya, Malaysia, Norway, the Philippines, Romania, South Korea, Thailand and the United States worked at the plant.
Norway has sent officials to search for five of its nationals still missing, while Japanese engineering company JGC Corp said 17 of its employees were still unaccounted for.
Philippine officials said 52 Filipino workers had survived, adding that it was still unclear if any Filipinos were among the dead.
The Algerian military operation that started on Thursday was criticized by some countries whose citizens were held hostage.
But French Foreign Minister Laurent Fabius later said he felt "shocked" that "it is the Algerians who are being called into question."
"There must be no impunity for terrorists," he told Europe 1 radio. "These are killers. They rob, they rape, they ransack."
US President Barack Obama had said that "the blame for this tragedy rests with the terrorists who carried it out, and the United States condemns their actions in the strongest possible terms."
Al-Said said the West had "appreciated" Algeria's handling of the crisis. "The Western capitals had expressed much reservations at first because they were not aware of the situation on the ground."
Algeria, which suffered an Islamist insurgency in the 1990s, had declared from the outset it would not negotiate with the militants.
German Foreign Minister Guido Westerwelle voiced "deep condolences" for the victims and their families.
At the Vatican, Pope Benedict XVI prayed for an end to "massacres against unarmed civilians," without specifically mentioning Algeria or the conflict in Mali.
In a survival story from the drama, a 57-year-old Norwegian man said he and seven others escaped and walked through the desert for 15 hours, the Norwegian newspaper VG reported.
The man from the city of Bergen said they had marched east for about 50 kilometres before reaching a town where, dehydrated and exhausted, they received medical help and phoned their families.