AFP troops in deadly clash with Abu Sayyaf

At least 12 people have been killed, including seven government troops, in fresh clashes as military stepped up offensive against rebels in the southern Philippines, officials say.

The fighting on Saturday in Sulu province's coastal town of Patikul between the military and members of Abu Sayyaf, an al-Qaeda-linked group, also wounded nine other marines and 10 fighters.

Jose Canbre, a local military leader, said that his team of marines ran into an Abu Sayyaf unit in the village of Tugas as government forces tracked members of the group suspected of recent kidnappings.

Domingo Tutaan, a military spokesman, told the AFP news agency: "It was an early-morning firefight. Our forces were tracking those responsible for some recent kidnappings in the area, including the wife of a soldier."

The social worker wife of a marine had been freed unharmed by the Abu Sayyaf on nearby Basilan island two days after her abduction, Tutaan said.

Reinforcement troops were hunting down the fleeing fighters, who were believed led by Julaswan Sawadjaan, an Abu Sayyaf leader blamed for kidnappings for ransom, including of a Jordanian journalist and two European tourists, who are still being held by the group.

A son of Sawadjaan was believed to have been killed in the clashes, Canbre added.

Abu Sayyaf is blamed for the worst attacks in the country, including the bombing of a ferry in Manila Bay.

Philippine security forces, backed by US troops, have stepped up offensives against Abu Sayyaf, which has also threatened to attack US-financed development projects.