Gunmen in camouflage stormed a plywood factory and abducted three workers Tuesday, a day after suspected Muslim militants beheaded a kidnapped schoolteacher on a nearby southern Philippine island, officials said.

About 20 assailants broke through a wooden fence and took away three men from the factory in coastal Maluso town on Basilan Island, military spokesman Maj. David Hontiveros said.

The latest abductions in the restive southern region, where al-Qaida-linked Abu Sayyaf militants have evaded U.S.-backed Philippine offensives, came as the military promised a swift retaliation for the beheading of a teacher whose family failed to raise ransom money on Jolo Island.

The severed head of Gabriel Canizares, 36, was left in a bag at a Jolo town gas station Monday, three weeks after suspected Abu Sayyaf militants stopped a passenger minibus and dragged him away in front of his colleagues.

Hontiveros refused to say if the Abu Sayyaf also was suspected in the Basilan attack. The kidnappers and hostages, including two factory managers, were moving on foot and authorities were tracking them, said Basilan Vice Gov. Al Rasheed Sakalahul. He suspected ransom was the motive for the attack.

Beside the Abu Sayyaf, which is notorious for bombings, kidnappings and beheadings, members of a large Muslim separatist group also operate on Basilan.

Although the Moro Islamic Liberation Front is currently engaged in peace talks with the government on ending decades of a bloody Muslim insurgency in the predominantly Roman Catholic nation, the military has in the past accused its Basilan unit of joining hands with the smaller but more brutal Abu Sayyaf.

The Abu Sayyaf, which is suspected of receiving funds from al-Qaida, is believed to have about 400 fighters.

Despite years of U.S. military training and assistance, Filipino troops have struggled to contain the militants, who have recently intensified attacks on Jolo, blowing up bridges, firing mortar shells and setting off roadside bombs.