An air force OV-10 bomber plane spotted about a hundred armed Moro Islamic Liberation Front (MILF) members massing in Kalamansig town on the southern island of Mindanao and dropped a bomb on them, said Lieutenant Colonel Julieto Ando.

'They were planning to attack our soldiers so we launched the air offensive,' said Mr Ando, adding that troops spotted about 10 bodies after the attack but were unable to recover them.

MILF spokesman Eid Kabalu confirmed that a military plane had attacked their forces but would not say if there were any casualties.

He denied the fighters had planned to attack military positions.

About 500 families were forced to flee the town because of the fighting, local officials in the area said.

The air strike was the latest in a series of skirmishes between the government and the 12,000-member MILF since large-scale fighting resumed in August after the Supreme Court suspended a draft accord intended to forge peace between the two sides.

More than 600,000 people were displaced in fighting that followed, while dozens of civilians, guerrillas and soldiers have been killed in continuing clashes. -- AFP