U.S. Green Beret commandos flew into a southern Philippine island infested with guerrillas yesterday and said although they were on a training mission, they were prepared to fight.

Clouds of dust rose into the air as giant Chinook helicopters carrying the elite strike force of the U.S. army landed at a military base near Isabela, the capital of Basilan island.

Crouched in the bush surrounding the landing pad was an advance guard of U.S. soldiers, fingers on the trigger, to provide security.

The southern Philippines is dotted with guerrilla and bandit gangs. At least eight people were wounded in three grenade attacks on Saturday night and yesterday, said Colonel Roland Detabali, a military spokesman.

On Saturday, suspected Abu Sayyaf guerrillas bombed a market on the nearby island of Jolo and lobbed a grenade into a cinema in Zamboanga city, killing at least one person and wounding dozens.

Basilan is one of the strongholds of Abu Sayyaf guerrillas, involved in kidnapping and random bombings.

Washington says they are linked to Osama bin Laden's Al Qaida network and its deployment of troops in the Philippines, a former colony and one of its closest allies in Asia, is the biggest expansion of the war against terror since the campaign in Afghanistan.

"This is a training mission," said special forces Sergeant Major Vic Allen.

Asked about the possibility of clashes with the Abu Sayyaf during the six-month exercises, he said: "I am prepared and my troops are prepared if that happens. Sure, there is risk involved, but I don't feel any undue risk."

About 30 commandos, camouflage backpacks strapped on and M-16 or M-4 carbines at the ready, flew into Basilan yesterday from the nearby city of Zamboanga.

The rest of the 150 to be deployed on the rugged, forested island will be here by the end of the week after which the exercises will begin in earnest.

They will be supported by 500 logistics staff stationed in Zamboanga and in the central city of Cebu.

Some 6,000 Philippine soldiers on Basilan will be trained in counter-terrorism, jungle warfare and other forms of combat. Some of the exercises will be in the field, where the possibility of an ambush by the Abu Sayyaf is rated high.

President Gloria Macapagal Arroyo has run into a storm of criticism for allowing U.S. troops into the country for what could turn out to be combat operations. She has replied sharply, calling the critics anti-national and "lovers of terrorists".

American and Philippine officials have insisted the deployment will be only a training exercise, but the U.S. troops will be armed and authorised to defend themselves.

Charge d'Affaires Robert Fitts, the top U.S. diplomat in the Philippines, however said last week that the troops were prepared for casualties.

"I don't say that lightly, I don't mean we are callous about it (but) we understand the implications of coming in," Fitts said. "There is the possibility of hostile contact but I would personally rate that as a possibility and not a probability."