Algeria's official news service, meanwhile, earlier claimed that 600 local workers were freed in the raid and half of the foreigners being held were rescued. Many of those locals were reportedly released on Wednesday, however, by the militants themselves.
One Irish hostage was confirmed safe: supervising electrician Stephen McFaul, whose mother said he would not be returning to Algeria.
"He phoned me at 9 o'clock to say Al Qaeda were holding him, kidnapped, and to contact the Irish government, for they wanted publicity. Nightmare, so it was. Never want to do it again. He'll not be back! He'll take a job here in Belfast like the rest of us," said his mother, Marie.
Dylan, McFaul's 13-year-old son, started crying as he talked to Ulster Television. "I feel over the moon, just really excited. I just can't wait for him to get home," he said.
In Washington, White House Press Secretary Jay Carney said the Obama administration was "concerned about reports of loss of life and are seeking clarity from the government of Algeria."
Japan's Prime Minister Shinzo Abe protested the military raid as an act that "threatened the lives of the hostages," according to a spokesman.
Jean-Christophe Gray, a spokesman for British Prime Minister David Cameron, said Britain was not informed in advance of the raid but described the situation as "very grave and serious." French President Francois Hollande called it a "dramatic" situation involving dozens of hostages.
Norwegian Prime Minister Jens Stoltenberg would not criticize the Algerian operation but said he wished the Norwegian government would have been notified before it started. He added that while Algeria has declined medical help, Norway will send a plane with medical equipment and personnel.