Four separatist rebels have been killed in the latest violence in Indonesia's troubled province of Aceh, security authorities said.

Soldiers killed four suspected members of the Free Aceh Movement (GAM) in a gunfight Wednesday in Aceh Besar district, said military spokesman Lieutenant Colonel Firdaus.

Firdaus told the Antara news agency the skirmish broke out after the troops crossed paths with dozens of GAM rebels in the area. A local GAM commander was among the four killed rebels. Troops also confiscated three automatic rifles and 800 bullets, Firdaus said.

GAM has waged a guerrilla war for an independent state in Aceh since 1976. Aceh, an oil- and gas-rich province on the north of Sumatra island, has been wracked by violence between separatist rebels and security forces. More than 1,600 people have died this year alone.