A former Algerian militant leader Mustapha Kertali has been seriously wounded by a car bomb in Larba, 25km south of the capital, Algiers.
President Bouteflika granted former Islamists amnesty
His car exploded after he had attended morning prayers at his local mosque.
Mr Kertali, who is in intensive care, worked with various armed groups during Algeria's civil insurgency until a 1999 peace accord, after which he disarmed.
He became a backer of President Abdelaziz Bouteflika, who granted former Islamist militants amnesty.
The BBC's Mohamed Areski Himeur in Algiers says it is not known who planted the bomb.
It may have been the work of active Islamists who consider him a traitor for giving up the fight, he says.
It could also be committed by relatives of victims of those killed during the time when he headed an armed group.
Mr Kertali became mayor of Larba in 1990 for the banned Islamic Salvation Front (Fis), which was later disbanded when the party looked set to win general elections.
Mr Kertali was a member of the Armed Islamist Group (GIA) and then went on to join the armed wing of Fis.
Our correspondent says Mr Kertali has become a well-known personality in Larba after returning to civilian life, acting as a kind of parallel mayor.
An estimated 150,000 people died in a decade of civil unrest after the elections were cancelled.
Insecurity has been increasing in Algeria, and across North Africa, since the Salafist Group for Preaching and Combat (GSPC) re-launched itself as al-Qaeda in the Islamic Maghreb at the beginning of this year.