ALGIERS, Algeria (AP) — Algerian special forces launched a rescue operation Thursday at a natural gas plant in the Sahara Desert and freed foreign hostages held by al-Qaida-linked militants, but estimates for the number of dead varied wildly from four to dozens.

Militants claiming revenge for France's intervention against rebels in Mali seized the Ain Amenas natural gas complex on Wednesday, taking dozens of foreign workers hostage.

Algerian state television said Thursday that four captives, two Britons and two Filipinos, had died. But the militants said at least 35 hostages had died in the state's rescue attempt. There was no way to independently verify the toll in the remote location, 800 miles (1,300 kilometers) from Algiers.