The Philippine military chief has confirmed that wanted Filipino bomb-maker Basit Usman, who has links to the Indonesian-based Jemaah Islamiyah terrorist network and a suspect in deadly bomb attacks in the south, has been killed.

Washington has offered a $1 million award for Usman's capture and prosecution.

Gen. Gregorio Pio Catapang said Monday that infighting among Usman's bodyguards led to a firefight Sunday in southern Maguindanao province, near a designated safe area for the Moro Islamic Liberation Front, the largest Muslim rebel group that signed a peace deal with the government last year.

He says it was unclear how Usman was killed, and the military was investigating if he was already dead when Muslim rebels arrived to check on the firefight.