Manila: Philippine security forces killed as many as 42 rebels claiming links with IS and captured their stronghold during five days of fighting in the mountains of a southern island, an army spokesman said on Friday.
Three soldiers were killed and 11 wounded when the forces seized the bastion of an affiliate of Jemaah Islamiah, a Southeast Asian network of militants, in the province of Lanao del Sur.
"Our troops were able to seize a stronghold of the terrorists on Thursday night," the spokesman, Major Filemon Tan, told reporters by telephone from the southern island of Mindanao, estimating that about 42 militants had been killed.
"We are still pursuing the rebels, using armoured assets."
Tan said the army was shelling rebel positions with 105-mm howitzers on Friday, while air force planes dropped bombs and helicopters fired rockets near the town of Butig, a base of the country's largest rebel group, the Moro Islamic Liberation Front (MILF).
But the MILF stayed away from the skirmishes and helped about 8,000 people displaced from their homes when the fighting began on February 20, the military said.
The Philippines signed a peace deal with the MILF in March 2014, ending 45 years of conflict that killed more than 120,000 people, displaced 2 million and stunted growth in the poor but resource-rich south.
Army and police officials believe some rebel factions, including the small but violent Abu Sayyaf group, have pledged allegiance to IS militants in Iraq and Syria, but say they have found no evidence to support this.
Elsewhere in Mindanao, soldiers were also chasing the Abu Sayyaf group, which is holding captive several foreigners, including a Japanese, a Dutch national, two Canadians and a Norwegian.