Washington ? The Bush administration has agreed to intensify U.S. military operations in the Philippines by permitting American forces to join in the hunt for Muslim guerrillas, but it has declined a request by top generals to keep troops there beyond the end of July, defense officials said Wednesday.

The Americans are still constrained by a clause in the Philippine constitution that forbids foreign troops from engaging in combat except in self-defense. But they are at risk of coming under fire as they patrol for members of the separatist group Abu Sayyaf, said defense officials who asked not to be identified.

The Green Berets will also begin instructing Philippine troops in smaller groups than at the battalion level, permitting more intense training than has been the case since the six-month exercise began in February.

Other details of the changes in the counterterrorism training mission on Basilan Island are still being worked out in consultation with members of Congress and the Philippine government.

The change in rules was designed in part to satisfy Philippine government and army officials who wanted the U.S. forces to take a more direct role in the effort to track down Abu Sayyaf rebels. President Bush approved the plan after a White House briefing Tuesday, in keeping with the emerging administration policy of pre-emptively striking potential terrorists.

The change in policy will increase the U.S. presence in the Philippines by no more than 60 troops, the Pentagon said. There are nearly 1,000 U.S. troops in the region, including more than 600 Special Forces troops.

Also Wednesday, Philippine marines found one of four Indonesians abducted two days earlier from a tugboat in the country’s latest kidnapping.

Soldiers found Ferdinand Joel unharmed, hiding in a coastal village on the southern island of Jolo after escaping late Tuesday from his captors’ forest hideout, said marine Brig. Gen. Teofilo de los Santos. Officials said Joel apparently escaped after he asked to relieve himself in the bushes.

Residents in Nangkaan hid him in a hut and notified authorities after he wandered into the village, de los Santos said. A marine rescue team found him trembling in fear, he said.

Joel, the tugboat’s second officer, was later flown to Zamboanga, about 75 miles north of Jolo.

There was no immediate word on the fate of the three other Indonesians and their captors.