At least 48 hostages are now thought to have died in a four-day siege at an Algerian gas plant, as reports say that 25 bodies found at the complex on Sunday were all those of captives.
It had initially been unclear whether the bodies found were those of hostage-takers or staff at the facility.
A search is continuing at the In Amenas gas plant, where as many as 20 hostages remain unaccounted for.
Five suspected Islamist attackers were reportedly arrested on Sunday.
The Algerian authorities had said on Saturday that all 32 hostage-takers had been killed. The suspected organiser of the attack, Mokhtar Belmokhtar, has said in a statement that 40 militants took part.
The siege was ended in a raid by troops on Saturday. Officials say a definitive death toll will be released later.
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.
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.
‘Production to resume’
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.
The private TV channel Ennahar said security forces had discovered the bodies of 25 hostages as they searched the complex for booby-traps and mines.
The militants had threatened to blow up the site and kill their hostages, officials said.
Belmokhtar, who is not thought to have been among the actual attackers, said his group had carried out the attack. He was speaking in a video message carried by the Mauritanian website Sahara Media.
The website said the video had been recorded on 17 January while the siege was still going on but not posted on the website.
It shows Belmokhtar, who has convictions in absentia for murder, kidnapping and terrorism, saying he was prepared to negotiate with Western and Algerian leaders if operations against Islamists in Mali were stopped.
