At least 48 hostages are now estimated to have been killed in a four-day attack on an Algerian gas plant, as reports say 25 bodies discovered at the plant Sunday were those of the captives, the BBC reported.

Five suspected attackers were reportedly arrested Sunday, after authorities said Saturday that all 32 hostage-takers had been killed. The siege ended after a raid by troops on Saturday, and an official death toll has not been released.

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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.

President Barack Obama and U.K. Prime Minister David Cameron blamed "terrorists" for the hostages' deaths. French Defense Minister Jean-Yves Le Drian described the hostage situation as an "act of war."

The kidnappers released a statement saying the assault on the gas plant was an act of retaliation for French involvement in the conflict with Islamist groups in neighboring Mali.

Read the full story at BBC News.

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