U.S., Philippine forces come under attack

U.S. forces have been training Philippine troops since February

WASHINGTON (CNN) -- Two U.S. Marines and an unknown number of Philippine military forces guarding a Navy construction depot came under attack and returned fire Monday on the Philippine island of Basilan, a Pentagon spokesman said.

Officials think the attack was staged by members of the Abu Sayyaf terrorist group, which has been linked to Osama bin Laden.

Pentagon officials said there were no injuries among U.S. and Philippine military personnel, though it appears there were a number of casualties among the suspected attackers.

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Details are still coming in about exactly what happened and who may have been involved, the officials said.

This is the first attack on American military personnel in the Philippines since U.S. forces arrived in February to train Philippine troops as part of the war against terrorism, a Pentagon official said.

The U.S. and Philippine troops were guarding a naval construction task force working to support the U.S. troops on Basilan, a small island in the southwestern Philippines.

The U.S. forces deployed to the Philippines number about 1,300, including military engineers working on infrastructure, such as building wells, landing zones and roads.