They are still working out how many hostages may have escaped, the nationalities of the killed. At least one killed has been confirmed an American.
Algerian troops have ended a siege at a gas facility in the Sahara desert killing 11 Islamist militants after they killed seven hostages, Algerian state news agency APS has said.
The hostages were summarily killed as the troops tried to free them, it said.
Foreign workers were among the hostages, but the nationalities of the dead are not known.
The militants had been involved in a stand-off since Thursday after trying to occupy the remote site.
APS has previously said 12 Algerian and foreign workers have been killed since rescue efforts began.
On Friday, 573 Algerians and about 100 of 132 foreigners working at the plant were freed, Algerian officials said.
About 30 foreigners remain unaccounted for, including fewer than 10 from the UK.
The militants themselves said before the raid that they had been holding seven hostages.