Twelve suspected Islamist extremists were killed by security forces in Algeria's Berber stronghold of Tizi Ouzou, 150 kilometres east of the capital Algiers, French media reported Friday.

The clash was the result of an ambush set for the armed Islamists by security forces, who afterwards confiscated a number of weapons and transmitters.

At least 21 people were injured in a suicide bomb attack last week in Tizi Ouzou.