U.S. military helicopters flew three wounded Filipino soldiers to safety after Muslim guerrillas ambushed a Philippine army patrol, officials said Saturday.

It was the first known occasion that U.S. troops involved in a counterterrorism training exercise in the southern Philippines played a role – though an indirect one – in that country's war with Abu Sayyaf guerrillas, who have been linked to the Al Qaeda terrorist network.

About 660 U.S. soldiers are training Philippine troops to better fight the Muslim rebels and rescue two Americans and a Philippine woman who have been in their hands for more than nine months.

Maj. Noel Detoyato, a Philippine military spokesman, said Abu Sayyaf guerrillas ambushed the Philippine army patrol after midnight in a jungle off Bolansa village on the small southern island of Basilan. In a 15-minute gunbattle, one soldier was killed and three were wounded.

Two U.S. Pave Hawk helicopters with night-flight capabilities flew to Basilan from their temporary base in the nearby city of Zamboanga. By the time they arrived, the fighting had stopped, and they did not come under fire, Detoyato said. The Pave Hawks are a version of the popular Army Black Hawk helicopter.

While waiting for the helicopters to arrive, the three soldiers were treated by U.S. Special Forces soldiers deployed with the Philippine army unit at a site about 1 miles from the fighting, Detoyato said.

The U.S. soldiers on the ground also guided the helicopters to a safe landing zone away from possible hostile fire, Detoyato said.

Brig. Gen. Donald Wurster, commander of U.S. troops training Filipinos, said the helicopter took the three wounded soldiers and their fallen comrade to a military hospital in Zamboanga.

He said the Philippine military asked for the help, and "we supported that request, of course."

Philippine military helicopters, mostly Vietnam War relics, lack night-flight capabilities, and soldiers have often bled to death while awaiting morning evacuation. Both sides had earlier agreed to use Philippine military helicopters during the day for medical evacuations and U.S. helicopters at night.

Detoyato said the Filipino soldiers were ambushed as they marched to establish a forward base in the northwest of Basilan Island. The island is home to about 60 Abu Sayyaf guerrillas who hold three hostages – Wichita, Kan. couple Martin and Gracia Burnham and Philippine nurse Ediborah Yap.