The militants fled before additional troops arrived. It was the second attack by suspected Abu Sayyaf gunmen in recent days, after two Abu Sayyaf militants on a motorcycle lobbed a grenade that killed a marine and wounded two others in Sulu's Jolo town on Sunday.
The militants now hold about 17 captives in their jungle strongholds in predominantly Muslim Sulu, including two European bird watchers and a Jordanian journalist who were kidnapped last year.
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 Indonesian-based Jemaah Islamiyah.
U.S.-backed military offensives have crippled the Abu Sayyaf in recent years, but it remains a key security threat. Washington lists the group as a terrorist organization.