MANILA (Reuters) - A senior Abu Sayyaf operative and four members of the militant group believed to be behind the deadly bombing of a church in the southern Philippines surrendered to authorities over the weekend, the national police chief said on Monday.

A Philippine Army member inspects the damage inside a church after a bombing attack in Jolo, Sulu province, Philippines January 27, 2019. Armed Forces Of The Philippines - Western Mindanao Command/Handout via REUTERS

Kammah Pae, whom authorities believe to have aided an Indonesian couple in the Jan 27 suicide attack, gave himself up to government troops, Oscar Albayalde said.

“He was forced to surrender,” Albayalde told a media briefing. “He probably didn’t want to die during the military offensive.”

Philippine troops killed three suspected Abu Sayyaf militants and suffered five fatalities in a firefight on Saturday in Patikul, a town in the province of Sulu as troops pursued those behind the church attack.

Albayalde said Kammah denied involvement in the twin bombings at the Jolo cathedral that killed 23 people, including civilians and soldiers, but eyewitnesses’ accounts showed he escorted the Indonesian couple.

Security forces also retrieved an improvised explosive device (IED) and components from his home, Albayalde added.

The five suspects will face multiple murder charges, among others, Albayalde said.

However, the investigation into the church bombing in Sulu, a known stronghold of the Abu Sayyaf group, is “far from over,” he added.

Abu Sayyaf is a militant organization notorious for kidnappings and extremist factions and has pledged allegiance to Islamic State.

“There are more pieces of evidence that need to carefully examined,” Albayalde said.

Before Philippine President Rodrigo Duterte suggested on Tuesday that the twin explosions may have been a suicide attack, military and police said the bombs within and outside the church appeared to have been detonated remotely.

A few days later, Duterte’s interior minister, Eduardo Ano, said that suicide attack was carried out by an Indonesian couple with the help of Abu Sayyaf.

That would be in line with a claim of responsibility by Islamic State via its Amaq news agency early on Monday.