The US state department has confirmed the deaths of three hostages held at a gas plant in Algeria, while another seven US nationals are known to have survived, the agency said.
Those lost are identified as Victor Lynn Lovelady, Frederick Buttaccio and Gordon Lee Rowan, State Department spokeswoman Victoria Nuland said in a press statement.
Local reports said Buttacio and Lovelady were from the Houston area, while Rowan was from Oregon.
"..The blame for this tragedy rests with the terrorists who carried it out, and the United States condemns their actions in the strongest possible terms," Nuland said.
A multinational group of terrorists that killed at least 38 hostages, including three Americans, at a gas complex in Algeria planned to blow up the site and escape into neighboring Mali with their captives, according to the first official account of the raid cited by Bloomberg.
Japan's Prime Minister Shinzo Abe said seven Japanese were killed according to the Kyodo news agency reported. In addition, six Filipinos, at least three Britons, two Romanians, one French security worker and a Colombian were slain, according to the news wire.
US defence secretary Leon Panetta acknowledged the deaths in an interview following the inauguration of President Barack Obama, according to the AP.
"That just tells us that al-Qaida is committed to creating terror wherever they are and we've got to fight back," he told the news wire.
Other governments have said 17 people remain unaccounted for, according to the Associated Press, and reports of the number killed have varied since the Algerian forces moved against the militants.