The army said the Abu Sayyaf group had planned to snatch up to a dozen tourists around Easter Sunday when resorts are packed.
PIC: A soldier runs after retrieving the rifle of a colleague after clashes in the village of Napo, Inabanga town, Boloh province, in the central Philippines. (AFP)
Islamic militants who landed on a Philippine tourist island triggering deadly clashes with security forces had planned to stage a mass kidnapping, the military said Wednesday as it pursued five fighters still on the loose.
The army said the Abu Sayyaf group, notorious for a kidnap-for-ransom spree that has targeted foreigners, had planned to snatch up to a dozen tourists around Easter Sunday when resorts are packed.
The group of 11 gunmen landed by boat on Bohol -- one of the country's top tourism spots -- sparking a gunbattle with security forces on Tuesday that left six insurgents dead and also killed three soldiers and a policeman.
Five Abu Sayyaf gunmen, along with an unknown number of local collaborators, remain at large after the clashes which took place in a rural district, said military chief of staff General Eduardo Ano.
Ano said the gang, which arrived on three boats, had planned to acclimatise in the area and send scouts into resorts to scope out kidnapping targets.
"They are expecting probably to kidnap four or five persons per boat, so at least 10 to 12 kidnap victims was their (overall) plan," he said.
The Abu Sayyaf launched the strike from their remote stronghold on the lawless southern Philippines island of Jolo, which is about 500 kilometres (300 miles) away from Bohol.
The island is just half an hour's boat ride from Cebu, another major tourism draw. The incursion is the first on a major destination in recent years by the group, which pledges allegiance to the Islamic State.
Ano said the Bohol plan was put into motion late last week as millions of local and foreign tourists prepared to hit the country's beaches ahead of the Easter holidays.
Philippine intelligence agencies got wind of the plot last week, and alerted the military and foreign counterpart agencies, though authorities lost track of the gunmen in the open seas.
The US and Australian governments later warned their citizens about possible "terrorist" abductions in Bohol and Cebu.
Ano said the five remaining fighters fled after an overnight siege near a remote village.
"They are all running for their lives," he said.
Helicopter gunships were used to bomb the militants, who fought back with high-end sniper rifles while holed up in a concrete house, according to officials.
Ano said that among the dead was a key Abu Sayyaf leader known by his alias Abu Rahmi. The claim could not be independently confirmed.
He said Abu Rahmi was behind a 2015 raid on the southern island resort of Samal in which four tourists -- two Canadians, a Norwegian and a Filipina -- were snatched.
The two Canadian men were beheaded last year while the Norwegian man and the Filipina were freed unharmed.
Ano said Abu Rahmi's group also attacked a German couple on a yacht at sea last year, murdering the woman on board and taking the man hostage. He was later killed.
Authorities in Cebu, an island of nearly five million people, warned their citizens about potential kidnapping raids following the Bohol attack.
"It is unlikely that they have the operational capability to do further damage now. However, other elements may exist," Cebu city Mayor Tomas Osmena said on his Facebook page.
As the government moved to contain the fallout on the lucrative tourism industry, the military said it would repel similar incursions.
Authorities said some 100 residents had fled the fighting. Hoteliers and visitors told AFP the incident had not affected tourist traffic on the island, though there was increased police security.
Over the past year the Abu Sayyaf has been expanding its activities from its main Jolo base in the south where the military launched an offensive last year.
Its boat-riding gunmen have been boarding commercial and fishing vessels and abducting dozens of foreign crew members.
Zachary Abuza, a Southeast Asian security expert at the National War College in the United States, told AFP the Abu Sayyaf had been regularly staging long-range kidnapping raids, including in Malaysia.
"They clearly benefit from the woefully inadequate maritime capabilities of the Philippine navy and coast guard," Abuza said.
"The amount of territory is very large, and these guys are moving on very small fast craft that blend in."