More than 20 foreigners were still either being held hostage or missing inside a gas plant today after Algerian forces stormed the desert complex to free hundreds of captives taken by Islamist militants.

More than a day after the Algerian army launched an assault to seize the remote desert compound, much was still unclear about the number and fate of the victims, leaving countries with citizens in harm's way struggling to find hard information.



Reports on the number of hostages killed ranged from 12 to 30, with anywhere from dozens to scores of foreigners still unaccounted for.

One American worker at the complex has been found dead, US officials said today as the Obama administration sought to secure the release of Americans still being held by militants on the third day of the hostage stand-off.



The officials identified the dead American as Frederick Buttaccio, a Texas resident, but said it was unclear how he died. They said US officials recovered Mr Buttaccio’s body today and notified his family.



US secretary of state Hillary Clinton said she spoke by telephone to Algerian prime minister Abdelmalek Sellal to get an update on Americans and others in danger at refinery. She said the “utmost care must be taken to preserve innocent life”.

The Obama administration confirmed that Americans were still being held hostage, even as some US citizens were being flown out of the country.

French foreign minister Laurent Fabius said this evening that a Frenchman was killed when the Algerian army stormed the gas plant. "The Algerian authorities have just informed us that one of our compatriots, Mr Yann Desjeux, unfortunately lost his life during the operation to free hostages," he said in a statement. "The lives of three others of our compatriots who were on the site during the terrorist attack have been saved," he added.



Norway's Prime Minister Jens Stoltenberg, eight of whose countrymen were missing, said fighters still controlled the gas treatment plant itself, while Algerian forces now held the nearby residential compound that housed hundred of workers.



Leaders of Britain, Japan and other countries expressed frustration that the assault had been ordered without consultation. Many countries were also withholding information about their citizens to avoid helping the captors.



Night fell quietly on the village of In Amenas, the nearest settlement, some 50 km from the vast and remote desert plant. A military helicopter could be seen in the sky.



An Algerian security source said 30 hostages, including at least seven Westerners, had been killed during yesterday’s assault, along with at least 18 of their captors. Eight of the dead hostages were Algerian, with the nationalities of the rest of the dead still unclear, he said.



Algeria's state news agency APS put the total number of dead hostages at 12, including both foreigners and locals.



Norway's Stoltenberg said some of those killed in vehicles blasted by the army could not be identified. "We must be prepared for bad news this weekend but we still have hope."



Northern Irish engineer Stephen McFaul, who survived, said he saw four trucks full of hostages blown up by Algerian troops. Mr McFaul is expected to arrive back in Northern Ireland tomorrow.



"We are still dealing with a fluid and dangerous situation where a part of the terrorist threat has been eliminated in one part of the site, but there still remains a threat in another part," British prime minister David Cameron said.



Four unnamed British men who were said to have been in the compound during the siege have given interviews on Algerian television about their experience.



“I think they did a fantastic job,” one man said. “I was very impressed with the Algerian army."



A second man said: “The gendarmes did a fantastic job. They kept us all nice and safe and fought off the bad guys."



The attack is a serious escalation of unrest in northwestern Africa, where French forces have been in Mali since last week fighting an Islamist takeover.



A local Algerian source said 100 of 132 foreign hostages had been freed from the facility. Some may be held hostage; others may still be hiding in the sprawling compound.



Two Japanese, two Britons and a French national were among the seven foreigners confirmed dead in the army's storming, the Algerian security source told Reuters. One British citizen was killed when the gunmen seized the hostages on Wednesday.



Those still unaccounted for today included 10 from Japan and eight Norwegians, according to their employers, and a number of Britons which Mr Cameron put at "significantly" less than 30.



The attackers had initially claimed to be holding 41 Western hostages. Some Westerners were able to evade capture by hiding.



They lived among hundreds of Algerian employees on the compound. The state news agency said the army had rescued 650 hostages in total, 573 of whom were Algerians.



"(The army) is still trying to achieve a 'peaceful outcome' before neutralising the terrorist group that is holed up in the (facility) and freeing a group of hostages that is still being held," it said, quoting a security source.



Multinational Insurgency



Algerian commanders said they moved in yesterday because the gunmen had demanded to be allowed to take their captives abroad.



The captors said their attack was a response to a French military offensive in neighbouring Mali. However, some US and European officials say the elaborate raid probably required too much planning to have been organised from scratch in the single week since France first launched its strikes.



Paris says the incident proves that its decision to fight Islamists in neighbouring Mali was necessary.



Al Qaeda-linked fighters, many with roots in Algeria and Libya, took control of northern Mali last year, prompting the French intervention in that poor African former colony.



The Algerian security source said only two of 11 militants whose bodies were found yesterday were Algerian, including the squad's leader. The others comprised three Egyptians, two Tunisians, two Libyans, a Malian and a Frenchman, he said.



US defence secretary Leon Panetta said those responsible would be hunted down: "Terrorists should be on notice that they will find no sanctuary, no refuge, not in Algeria, not in North Africa, not anywhere.... Those who would wantonly attack our country and our people will have no place to hide."



Warning of More Attacks



The kidnappers threatened more attacks and warned Algerians to stay away from foreign companies' installations, according to Mauritania's news agency ANI, which maintained contact with the group during the siege.



Hundreds of workers from international oil companies were evacuated from Algeria yesterday and many more will follow, said BP, which jointly ran the gas plant with Norway's Statoil and the Algerian state oil firm.



The overall commander of the kidnappers, Algerian officials said, was Mokhtar Belmokhtar, a one-eyed veteran of Afghanistan in the 1980s and Algeria's bloody civil war of the 1990s. He appears not to have been present.



Britain's Cameron, who warned people to prepare for bad news and who cancelled a major policy speech on Friday to deal with the situation, said he would have liked Algeria to have consulted before the raid. Japan made similar complaints.

Reuters/AP