MANILA (Reuters) - Philippine troops killed three suspected Abu Sayyaf militants and suffered five fatalities during a firefight on a remote southern island, the military said on Saturday.

The clash with more than 100 members of the Abu Sayyaf group broke out in the town of Patikul in the Sulu province at 11:30 a.m. as troops pursued those behind a church attack on Sunday, Colonel Gerry Besana, spokesman for the military’s Western Mindanao Command said.

The church bombing in Sulu, which killed 22 people and wounded more than 100 including civilians and soldiers, was a suicide attack carried out by an Indonesian couple, with help of the Abu Sayyaf group, Interior Minister Eduardo Año said on Friday.

Abu Sayyaf is a militant organization notorious for kidnappings and extremist factions and has pledged allegiance to Islamic State. Sulu province, in the country’s Mindanao region, is a known stronghold of the group.

The encounter in Patikul lasted nearly two hours, Besana said, with five soldiers and 15 militants also wounded.

Martial law has been in place in Mindanao since domestic and foreign fighters dressed in black outfits overran Marawi City in 2017 and clung on through five months of air strikes and street battles reminiscent of scenes in Syria and Iraq.