Zamboanga City, Philippines  - One soldier and three suspected Islamic militants were killed Thursday during a clash in the southern Philippines, a regional military chief said.

Nine Marines were also injured in the fighting that erupted when suspected Muslim Abu Sayyaf rebels attacked a military outpost in Panamao town on Jolo island, 1,000 kilometres south of Manila, Major General Benjamin Dolorfino said.

Dolorfino said troops recovered four assault rifles from the slain suspected militants.

On Tuesday, two American soldiers and one Filipino marine were killed in a landmine attack by suspected Abu Sayyaf guerrillas in nearby Indanan town.

The Abu Sayyaf is the smallest but most violent Muslim rebel group in the southern Philippines. It has been blamed for the worst terrorists attacks in the country. (dpa)