MANILA (Reuters) - United States-trained army commandos in the Philippines killed 10 Al-Qaeda-linked militants in a clash on a southern island, a military spokesman said on Thursday (Dec 31), as security forces intensify a search for foreign hostages.

A lieutenant was among eight Philippine soldiers killed or wounded in a clash with about 300 members of the Abu Sayyaf militant group on Jolo island late on Wednesday, spokesman Major Filemon Tan told reporters.

"Our troops are pursuing the Abu Sayyaf who broke into small groups and withdrew to the interior of the island," Maj Tan said, adding that 15 militants had also been wounded in the fighting. "This is part of our focused military operation to free foreign hostages held by the Abu Sayyaf."

Maj Tan said the Abu Sayyaf group is holding two Canadians, along with a Dutch citizen, a Norwegian and a Japanese.

Last month, they beheaded a Malaysian captive, prompting President Benigno Aquino to order intensified operations against the rebels.

Maj Tan said US-trained scout rangers had assaulted a rebel lair, triggering a three-hour battle. Troops later fired artillery at the fleeing rebels.

There were no indications any of the hostages were in the area, he said.

The small but violent Abu Sayyaf, known for kidnappings, beheadings and bombings, is one of the most hardline Muslim rebel factions in the Muslim south of the largely Christian Philippines.

Two weeks ago, 13 Abu Sayyaf rebels were killed in a clash on nearby Basilan island while 14 people died on Christmas eve when another Muslim rebel faction, Bangsamoro Islamic Freedom Fighters, staged attacks on Mindanao, the main southern island.

The government signed a peace deal with the largest Muslim rebel group, the Moro Islamic Liberation Front, in March, promising autonomy in the south and ending a 45-year conflict that killed 120,000 people and displaced two million.

Both the Abu Sayyaf and Bangsamoro guerrillas are opposed to the peace agreement and have vowed to set up an Islamic state in the southern Philippines.

While long known for links with Al-Qaeda and its South-east Asian affiliates, the Abu Sayyaf group recently swore allegiance to Islamic State militants in Iraq and Syria.