"Nearly 650 hostages seized in the attack carried out on Wednesday by a terrorist group... among them 573 Algerians and more than half of the 132 foreign hostages, were freed" by Algerian special forces, the APS news agency reported.
The final number of foreigners who managed to escape from the kidnappers was unavailable, it said, as some were still either in hiding or being held hostage inside the industrial complex.
"(The army) is trying to reach a peaceful solution before neutralizing the terrorist group that is holed up in the plant and freeing a group of hostages still being held there," APS said.
The In Amenas plant, which is jointly operated by British oil giant BP, Norway's Statoil and Algeria's Sonatrach, has now been put out of service to avoid the risk of explosion.
The army rescue operation was launched on Thursday after the kidnappers seized the hostages at the site in what they said was retaliation for Algeria's support for French air strikes in Mali.
The kidnappers said 34 captives were killed in the military assault, but an Algerian security source described that toll as "fantasy," while stating that 18 of more than 30 gunmen involved in the hostage-taking operation were killed.
International criticism is mounting of the Algerian government's handling of the attack on the plant amid reports that many foreign hostages may have been killed in the army raid.
MOL/