Islamist militants have killed 11 Algerian soldiers in an ambush on a patrol in mountains east of the capital Algiers, security sources say.
Reuters news agency reports the troops were searching for militants in Tizi Ouzou region when they were attacked.
It is believed the attack was carried out by fighters from al-Qaeda in the Islamic Maghreb (Aqim).
It was one of the deadliest attacks on the Algerian military for several years.
The attack came days after President Abdelaziz Bouteflika, 77, was re-elected for a fourth term following a campaign that stressed security as a key policy.
A 10-year civil war was fought between the government in Algiers and Islamist insurgents in the 1990s, but now the militants are largely confined to isolated regions such as the mountains east of Algiers.
AQIM, al-Qaeda’s north African branch, is mostly based in southern Algeria but over the past few months the army has killed several militants in the north-eastern mountains, and security sources say some fighters have been found with weapons traced to neighbouring Libya.