Philippine President Gloria Arroyo has suspended the governor of the autonomous Muslim region, after former rebels there clashed with the military. Manila is investigating whether the governor is responsible for the fighting, which has reportedly killed 55 people.

President Arroyo's spokesman, Roberto Tiglao, says the governor of the Autonomous Region of Muslim Mindanao has been placed on preventive suspension. Mr. Tiglao says the government is investigating to see if Nur Misuari was directly responsible for the clashes with the military Monday.

Officials say, however, that Mr. Misuari is still governor.

The presidential adviser on the peace process, Eduardo Ermita, says Governor Misuari needs to publicly explain the incident and deny that he was involved in it. Mr. Ermita says the government is considering bringing criminal charges against Mr. Misuari. "The police authorities are looking at the possibility of charging him with other crimes, such as probably rebellion or sedition, depending on the available evidence, because of the incident that cost the lives of more than 50 people," he said.

The Philippine military says hundreds of former rebels of the Moro National Liberation Front (MNLF) attacked a garrison on Jolo island, 1,000 kilometers south of Manila, Monday.

The clash came one week before the autonomous region in the southern Philippines is to elect a new governor. Governor Misuari opposes the election, saying it violates a five-year-old peace accord between the MNLF and the Philippine government. Under the accord, the MNLF laid down its arms in exchange for autonomy for Muslim Mindanao. Mr. Misuari was appointed governor as part of the accord.

The MNLF ousted Mr. Misuari as chairman last April, a move said to be supported by the Philippine government. Philippine officials accuse the governor of staging the attack to disrupt next Monday's vote.