Military spokesman Major Filemon Tan says 10 Abu Sayyaf rebels were killed on Friday in Sulu province, but troops retrieved only three bodies.

Four were killed and nine wounded on the government side.

Tan says army units encountered some 150 militants in Patikul township and exchanged fire for 45 minutes until the extremists withdrew. Soldiers then pounded the rebels' position with artillery fire and put up checkpoints as they pursued the militants.

The Abu Sayyaf, which is blacklisted by the US and the Philippines as a terrorist organisation, holds more than a dozen foreign and local hostages.