Algeria's official news agency says a series of bomb blasts has killed at least six people and wounded several others.
Several of the attacks Tuesday targeted police stations in the Boumerdes and Tizi-Ouzou districts east of the capital, Algiers.
There was no immediate claim of responsibility.
There have been frequent clashes between Algerian security forces and Islamist militants in the Boumerdes and Tizi-Ouzou districts.
Algerian authorities blamed the Salafist Group for Preaching and Combat for similar bomb attacks against police stations last October.
The group has refused peace offers and declared allegiance to al-Qaida.
Las month, the group announced on an Islamist web site that it was changing its name to Al-Qaida Organization in the Islamic Maghreb.
Two weeks ago, Algeria's security minister, Dahou Ould Kabilia, said the Salafist group posed no serious threat and vowed that it would be eradicated.
Some information for this report was provided by AFP and Reuters.