ISABELA (UPDATED) - Al Qaeda-linked militants in police uniforms set off bombs and fired at civilians on a strife-torn Philippine island Tuesday in violence that left 15 people dead, officials said.
The gunmen detonated two home-made bombs near a church and a school sports grandstand in Isabela city on Basilan island, in the latest show of force by the Abu Sayyaf network, which is blamed for the nation's worst terrorist attacks.
"I think (the attack) is meant to create havoc.... Definitely it falls under terrorism," Major General Juancho Sabban, head of the Philippine Marines, told reporters in Manila.
Isabela city mayor Cherry Akbar told reporters that 15 people were confirmed dead, including five militants who were apparently killed by one of their own bomb blasts.
Six civilians were also killed in the explosions, while three soldiers and a policeman were killed in gun battles with the militants, Akbar said.
At least 25 militants wearing police uniforms were involved in the attacks, according to the region's military chief, Lieutenant General Ben Dolorfino.
However, Dolorfino said the Abu Sayyaf's main goal may have actually been to kidnap a high-profile person in Isabela, and that the explosions could have been intended as a diversion.
"It looks like they were planning to kidnap someone but they did not expect our troops to react immediately," Dolorfino said, adding he did not know the target of the suspected abduction plot.
The militants sprayed bullets at terrified civilians scrambling for safety, and engaged in a gun battle with security forces on the outskirts of Isabela that lasted for at least three hours, according to military chiefs.
The first bomb went off about 10:30 am (0230 GMT) outside an education department building near a high school sports grandstand, provincial police chief Antonio Mendoza said in Isabela.
He said the second, rigged to a motorcycle left near a Roman Catholic cathedral, went off minutes later as security forces chased the suspects.
"It heavily damaged the church," Mendoza said.
A third bomb placed near a judge's house and a bus terminal was safely detonated by soldiers.
Basilan, an impoverished island of nearly half a million people, is part of the southern Philippines' Mindanao region, where the Abu Sayyaf and other Muslim rebel groups are fighting for an independent homeland.
Hundreds of US troops have been stationed in Mindanao since the end of 2001 to train and equip the Philippine military to combat the Abu Sayyaf.
Their arrival came after a series of Abu Sayyaf-led abductions, including the kidnapping of three Americans from a southwestern Philippine island resort.
Two of the US hostages were killed, one by beheading.
The Abu Sayyaf was also blamed for the bombing of a passenger ferry in Manila Bay in 2004 that killed over 100 people, the nation's most deadly terrorist attack.
US help has led to the deaths of senior Abu Sayyaf leaders and the Philippine military says the group now has only about 300 active militants, down from about 1,000 a decade ago.
However the country's police chief, Jesus Verzosa, warned last month the Abu Sayyaf was increasingly using improvised bombs to counter battlefield losses.
Other recent attacks blamed on the Abu Sayyaf include two roadside bombs that killed a Philippine soldier and wounded 12 other people on Basilan in February.
Last September an improvised explosive device blamed on the Abu Sayyaf killed a Philippine Marine and two US soldiers on a training mission on neighbouring Jolo island.