Thirteen assailants and two soldiers were killed when a little-known Islamic militant group attacked a military outpost in the lawless southern Philippines on Sunday, the army said.
About 50 men attacked the Marine outpost on the strife-torn island of Jolo before dawn but the troops fought back, driving them off, said regional military spokesman Lieutenant Colonel Randolph Cabangbang.
He said two soldiers were killed in the gun battle, and the military had recovered 13 of the assailants' bodies.
Cabangbang identified the attackers as members of the "Awiiyah group", which he described as a "radical" organisation with links to the Abu Sayyaf.
He would not provide further details on the group, other than to say it was trying to take control of the territory from the military in a remote section of Jolo.
The Abu Sayyaf is a local Muslim extremist group founded with the help of the Al-Qaeda network in the 1990s which has been linked to the worst terror attacks in Philippine history.
This includes a ferry bombing that killed more than 100 people in 2004. But Jolo and other parts of the southern Philippines are home to a wide a range of armed Muslim groups, many of which work together or help each other and are regularly involved in kidnappings, drugs and other crimes to survive.
The Philippines is Asia's Roman Catholic outpost but there are about four million Muslims who live mainly in the south.
An insurgency has waged for four decades with Muslims aiming for independence or an autonomous substate in the southern areas they say are their ancestral homelands.
But the main Muslim rebel group is involved in peace talks with the government, and insists it has no ties to radical groups such as the Abu Sayyaf, which is listed by the United States as a terrorist organisation.
US special forces have been stationed in the southern Philippines for a decade to help train the military in combating the Abu Sayyaf, although they are not allowed to have a combat role.
Cabangbang said the gunmen in Sunday's attack had apparently miscalculated the timing of the assault on the military outpost, where between 60 and 90 Marines were stationed.
"They probably attacked based on the wrong information. They may have thought the soldiers were still getting up but at that hour, there are already a lot of soldiers who are active," said Cabangbang.
Five soldiers were also wounded in the attack and had to be flown to a hospital by helicopter, according to Cabangbang.