Strong winds from the propellers of two descending CH-47 'Chinook' American helicopters peeled off the roof of a guardhouse at the Edward Andrews Air Base, an incident that attracted onlookers and created a traffic jam in the major thoroughfare of Zamboanga City, southern Philippines.

Residents woke up to the sound of the big helicopters as they hovered above the air base. Apprehensive motorists stopped, children rushed to the scene, and clapped their hands as if they were watching a movie in the making, eyewitnesses said.

"No one was hurt," said Air Force head, Colonel Fredesvindo Covarrubias, spokesman of the U.S.-Philippine wargames.

The helicopters flew in from the central Philippines to unload troops and equipment for the joint Philippine-U.S. military exercises, which many said were meant to deter some 60 to 70 hostage-taking members of the Abu Sayyaf Group in nearby Basilan.

Our Manila Bureau Chief adds: The first batch of 32 U.S. special strike force members will be deployed in Basilan tomorrow, after an overnight stay in Zamboanga City.

By next week, a total of 160 American soldiers will be in Basilan, where the Abu Sayyaf group is holding a Filipina and two American missionaries hostage, said Marine Brig. Gen. Emmanuel Teodosio, co-director of the war games.

The entry of the American troops in Basilan is a major expansion of the U.S.' worldwide campaign against terrorism.

The Special Strike Force is an elite group composed of experts in unconventional warfare and used by the United States in hot spots worldwide.

The safety of the American troops in Basilan will be a major concern of the Philippine government, said Philippine military chief, General Diomedio Villanueva.

Mediamen are keen on monitoring the U.S. forces in Basilan because of a guideline which says they can fire back when attacked by the Abu Sayyaf. They are banned from directly taking part in the combat between the hostage-takers and the Filipino soldiers.

The joint exercise will be limited only to Basilan and Zamboanga City, but many Abu Sayyaf leaders have reportedly gone to nearby Jolo island.

About 200 American logistics and communications personnel are already in Zamboanga City. A total of 303 U.S. soldiers, mostly support and administrative staff, are now deployed in Cebu City, central Philippines.

By Monday, a 660-strong U.S. contingent is expected to arrive in Zamboanga City, a jumping board to Basilan for the training of Filipino soldiers who are fighting the Abu Sayyaf Group. There are some 60 to 70 hard-core Abu Sayyaf members.

"The U.S. troops may need a week or two to formulate training modules that will suit our troops. The Americans troops will constantly shuttle between Basilan and Zamboanga to fine-tune their training programmes," said Teodosio.

He added that a two-week preparation for the U.S.-Philippine wargames is ongoing.

Meanwhile, President Gloria Arroyo told critics "to give the joint exercises a chance", adding that they will eventually benefit the Filipino soldiers in combating terrorism.

At the same time, Arroyo dismissed reports that some Abu Sayyaf leaders have sent surrender feelers to the military out of fear that they will be targeted by the U.S-Philippine wargames.

The presdient congratulated herself for the drafting of guidelines of the war games, adding that previous joint exercises did not have the so-called term of reference, just a description of the training course.

"It was good that if finally came out and at least our people know them by now," Arroyo said.