By Hader Glang

ZAMBOANGA CITY, the Philippines

Suspected al-Qaeda-linked militants have killed a former combatant of a Moro Muslim rebel group in the Philippines’ troubled southern Sulu province, according to the military Saturday.

Brig. Gen. Alan Arrojado, Joint Task Group Sulu commander, said that Gaber Majang -- who had returned to civilian life after the Moro National Liberation Front (MNLF) signed a 1996 peace deal with the government -- was killed in a firefight the night before.

Arrojado said the clash broke out when a group led by Abu Sayyaf sub-leader Sibih Pisih swooped down on Majang’s residence in Indanan town, also resulting in the death of Pisih’s son and the wounding of a follower of Majang.

“They [Majang’s group] were fired on and harassed by the Pisih group," he added, without specifying how many people were on each side.

He said that Pisih’s group suspected Majang of being a military informant, and held him responsible for the killing of an Abu Sayyaf member known as Abu Quodama in a firefight earlier this month.

Some factions of the MNLF consider the 1996 deal with the government to have been betrayed by a 2014 agreement between its breakaway group, the Moro Islamic Liberation Front (MILF), and Manila.

In 2013, a group led by MNLF leader Nur Misuari laid siege to the predominantly Christian city of Zamboanga to protest the ongoing MILF-government peace process.

Concerns over the peace process have recently mounted as a law that would have sealed the 2014 deal was shelved earlier this month when Congress adjourned for campaigning for the May general election. "