A military convoy was ambushed on Wednesday by armed rebels on a highway near the port city of Bejaia in the Berber region some 250 km east of the capital Algiers, state radio reported.
The Salafist Group for Preaching and Combat (GSPC), aligned to the al-Qaida network, is based in the region and often stages its attacks there.
The ambush, unusual because it took place in the daytime, came only days after another convoy was attacked, killing three members of the security forces, according to newspaper reports.
"This is a setback for the forces, particularly because of the terrorists' ability to strike during the day in a country heavily guarded by the armed forces," said a security expert.
Authorities were not available for comment.