Algerian officials now say the Islamist takeover and military raid of a desert natural gas complex killed at least 80 people, including a large number of foreign hostages.

Officials combing through the complex found 25 more bodies Sunday, but they say the remains are so disfigured, it is hard to tell if they are militants or hostages.

Algerian forces captured five militants alive during Saturday's raid. Algeria's official news agency said the militants killed seven hostages during the raid, while Algerian troops killed 11 of the kidnappers. A number of militants and hostages were also killed earlier during the crisis. while other hostages escaped unharmed.

Militants seized the In Amenas gas complex Wednesday.

Islamist militant leader Mokhtar Belmokhtar claimed responsibility for the attack. In an Internet video posted on Sunday. He said he was acting in the name of al-Qaida and that 40 militants from Muslim and Western nations carried out the raid.

Belmokhtar said the attack was an answer to the French military operation against other al-Qaida-linked militants in Mali.

British Prime Minister David Cameron said Sunday that responsibility for the killings “lies squarely” with what he called the “terrorists who launched this vicious and cowardly attack.” French President Francois Hollande welcomed what he described as Algeria's “most appropriate” response to “coldly determined terrorists.”

Algerian Communications Minister Mohamed Said said the Islamist assailants came from six nations. He said said Algerian experts are tying to clear away landmines the militants laid around the gas complex.

The foreign hostages included Americans, Austrians, Belgians, Britons, Colombians, French, Japanese, Malaysians, Norwegians and Romanians. The complex is jointly run by Algerian, British and Norwegian firms.