Eleven Algerian soldiers were killed and 14 wounded when they fell into an ambush in the restive Kabylie region east of Algiers.

Three Algerian army soldiers on Sunday succumbed to injuries they had sustained in an ambush attack on their patrol in northern Algeria a day earlier, bringing the death toll to 14, according to the state-run news agency.

"As many as 11 soldiers died instantly while three others succumbed to their injuries," the agency quoted an unnamed security source as saying.

The army has launched a major operation to track down the attackers, he added.

The army patrol was returning to base after participating in securing Thursday's presidential polls, according to the source.

Earlier in the day, eleven soldiers were killed and 14 wounded when they fell into an ambush in the restive Kabylie region east of Algiers, a security sources said Sunday.

One extremist militant was also killed in the attack, which took place overnight at Iboudrarene as the troops were returning from a mission in the area, the sources said.

The attackers laid the ambush on a main road between two villages in the mountainous region where militants who battled the army during the civil war in the 1990s still operate.

Al-Qaeda in the Islamic Maghreb has also attacked security forces there.

Last week the army said it killed two "terrorists" near the village of Koukou, in the same area as Iboudrarene.

Sunday's attack came after ailing President Abdelaziz Bouteflika won a fourth term last week in an election marred by low turnout and allegations of fraud, with his main rival rejecting the result.

Discontent with the 77-year-old Bouteflika is most evident in Kabylie, where some 70 people were wounded in clashes on Thursday between police and youths seeking to disrupt the vote.