MOSCOW, January 19 (RIA Novosti) – More hostages have been released as the standoff between Algerian security forces and an al-Qaeda-backed Islamist group continues at a gas plant in southeastern Algeria.

Two Norwegian hostages were released, Helge Lund, head of the Norwegian energy company Statoil, which partly operates the plant attacked earlier this week by the Islamic insurgents, said at a briefing on Saturday.

The fate of six others remains unknown, Lund added, declining to specify how the two hostages were freed.

The news arrives amid a risky military rescue operation launched on Thursday by Algerian forces. One American hostage was confirmed dead, while Algerian authorities say more than 500 Algerians and nearly 100 out of about 130 foreign hostages had either escaped or were freed.

Dozens of foreign hostages, meanwhile, remained unaccounted for on Saturday.

Algeria has come under criticism from several countries over its handling of the rescue operation, many details of which remain unclear. The Algerian state news agency, APS, previously reported that 12 hostages have so far been killed during the operation.

The Algerian authorities have defended the rescue action, claiming their raid helped prevent more casualties, Algerian newspaper El Khabar reported Saturday.

The Islamist group, Signatories in Blood, is seeking an end to the French military intervention in Mali, where troops arrived last week to suppress a growing Islamist insurgency in the North African country.