Algerian state television says a suicide bomb attack has killed about 15 people and wounded more than 70 others.
Security officials say the attack occurred Thursday in the eastern town of Batna - shortly before President Abdelaziz Bouteflika was scheduled to visit.
Witnesses say the bomber was among a crowd of people waiting to see Mr. Bouteflika. The Algerian president later visited some of the wounded at a local hospital.
He condemned those who carried out the attack as "criminals" and said Algeria was committed to achieving national reconciliation.
Al-Qaida's North African branch has claimed responsibility for several recent attacks in Algeria.
Islamic militants have been fighting in Algeria since 1992. Violence has largely subsided in recent years, but the group al-Qaida Organization in the Islamic Maghreb continues to fight.
Some information for this report was provided by AFP and Reuters.