At least seven Filipino marines and four Abu Sayyaf militants were killed in a clash Saturday as the military launched an offensive against al-Qaida-linked gunmen who have been blamed for recent kidnappings and of trying to sabotage a road project in the southern Philippines.

Nine other marines and about 10 Abu Sayyaf fighters were wounded in the gunbattle that raged for an hour in a sparsely populated village on the fringes of the coastal town of Patikul in Sulu province, military spokesman Brig. Gen. Domingo Tutaan said.

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

A son of Sawadjaan was believed to have been killed in the firefight, Sulu's military commander, Col. Jose Cenabre, said, adding the marines initially had difficulty returning fire because the militants took cover near a row of houses.

Sawadjaan's men have been accused of last week's kidnapping of a Filipino marine's wife who works in a Sulu provincial hospital. The gunmen also recently abducted two government men working on a road project in Patikul. The two were freed last week but it was not clear if a ransom was paid, officials said.

While Abu Sayyaf abductions still occur, they are far fewer today than the massive kidnappings that terrorized Sulu and outlying provinces in the early 2000s when the group had many commanders and strong ties with terrorist organizations including the Indonesian-based Jemaah Islamiyah.

U.S.-backed military offensives have crippled the Abu Sayyaf in recent years, but it remains a national security threat. Washington has the group as a terrorist organization.