Two Scots are among four hostages reported to have been freed following an Algerian military raid at a desert gas plant.
State news agency the Algerian Press Service (APS) said two other hostages, from France and Kenya, were also released during the raid on Thursday.
The APS said Islamist militants came under fire from the army as they tried to drive away from the complex at In Amenas.
The operation is believed to have caused numerous casualties, and the APS said about half the foreign hostages held by militants had now been released.
Algerian state television quoted a hospital as saying four foreigners had been killed and seven wounded amid a confused picture of the crisis.
One British citizen was already confirmed dead in the hostage incident in which several others are caught up.
Earlier, there were reports that between six and 35 hostages and eight and 15 rebels had been killed in the fighting.
Algerian authorities reportedly confirmed "several deaths and injuries".
Prime Minister David Cameron said last night the country should be "prepared for the possibility of further bad news".