Zamboanga City, Philippines  - US troops pulled out Wednesday from a southern Philippine village where two American soldiers were killed in a landmine attack by suspected Islamic militants.

The Seabees, members of the Construction Battalions of the US Navy, left behind unfinished development projects in Kagay village in Indanan town on Jolo island, 1,000 kilometres south of Manila.

Major General Ben Dolorfino, a regional Philippine military commander, declined to say how many Seabees pulled out but noted that Filipino troops have been dispatched to guard the construction sites.

"The Seabees totally pulled out, but they are determined to continue with the projects," he said. "They will probably have to subcontract the remaining work."

Dolorfino said al-Qaeda-linked Muslim Abu Sayyaf rebels were suspected to be behind the landmine attack on Tuesday, which killed two US servicemen and a Filipino marine.

Two Filipino marines also were injured in the attack, which happened near a military outpost.

Dolorfino said additional troops have been dispatched to step up security at the outpost.

"We have hardened our detachments," he said. "We have added sufficient reactionary forces."

President Gloria Macapagal Arroyo ordered the police and the military to investigate the attack.

"We are very sad, and we mourn the death of the soldiers," deputy presidential spokesman Anthony Golez said. "The act was very shameless because they are doing a humanitarian mission."

Dolorfino said the slain US servicemen were inspecting projects worth more than 140,000 dollars in Kagay, including two school buildings and a 5-kilometre road.

Jolo island is a stronghold of Abu Sayyaf rebels, who have been the subject of US-backed counterterrorism operations by the Philippine military.

Hundreds of US troops have been stationed in Jolo and other areas in the southern Philippines since 2002 under a visiting forces agreement forged between Manila and Washington in 1998.

Philippine legislators, however, are demanding a renegotiation of the agreement, which failed to specify the period of stay of the visiting US forces or define what activities they may engage in in the country. (dpa)