MARAWI, Philippines, Dec 3, 2023 (BSS/AFP) - At least three people were killed and seven wounded in a bomb attack on a Catholic mass in the insurgency-plagued southern Philippines on Sunday, officials said.

The blast happened during a regular service at Mindanao State University's gymnasium in Marawi, the country's largest Muslim city, regional police Chief Allan Nobleza said.

"We're investigating if it's an IED or grenade throwing," Nobleza said, referring to an improvised explosive device.

Mindanao State University issued a statement condemning "the act of violence", as it suspended classes and deployed more security personnel on the campus.

"We stand in solidarity with our Christian community and all those affected by this tragedy," the university said.

Photos posted on the Lanao del Sur provincial government's Facebook page showed Governor Mamintal Adiong visiting "wounded victims of the bombing" at a medical facility.
 
Marawi city Mayor Majul Gandamra urged members of the Muslim and Christian communities to remain unified.

"Our city has long been a beacon of peaceful coexistence and harmony, and we will not allow such acts of violence to overshadow our collective commitment to peace and unity," Gandamra said in a statement condemning the attack.

The incident came after the Philippine military launched an airstrike on Friday that killed 11 Islamist militants from the Dawlah Islamiyah-Philippines organisation in Mindanao.

The military said Saturday the group had been planning to mount attacks in Maguindanao del Sur province.

Lanao del Sur and Maguindanao del Sur are part of the Bangsamoro Autonomous Region in Muslim Mindanao.

Militant attacks on buses, Catholic churches and public markets have been a feature of decades-long unrest in the region.

Manila signed a peace pact with the nation's largest rebel group, the Moro Islamic Liberation Front, in 2014, ending their deadly armed rebellion.

But smaller bands of Muslim fighters opposed to the peace deal remain, including militants professing allegiance to the Islamic State group. Communist rebels also operate in the region.

In May 2017, hundreds of pro-IS foreign and local gunmen seized Marawi.

The Philippine military wrested back the ruined city after a five-month battle that claimed more than a thousand lives.

Nobleza said police were investigating whether Sunday's attack was linked to Friday's air strike.

Another line of inquiry was whether remnants of the Marawi siege by Maute and Abu Sayyaf militant groups were involved, Nobleza said.