At least three people were killed and dozens wounded in a bomb attack on a Catholic mass in the insurgency-plagued southern Philippines on Sunday, with President Ferdinand Marcos blaming “foreign terrorists”. The blast occurred during a regular service at Mindanao State University’s gymnasium in Marawi, the country’s largest Muslim city, regional police Chief Allan Nobleza said. The university condemned the act of violence and suspended classes while deploying more security personnel on campus. Three people were killed and more than 40 wounded were being treated in hospital. President Marcos condemned the attack as “senseless” and “heinous”, while Marawi city Mayor Majul Gandamra urged members of the Muslim and Christian communities to stay united. Police were investigating whether the bombing was a revenge attack for a Philippine military airstrike that killed 11 Islamist militants on Friday, and whether remnants of militant groups involved in the 2017 siege of Marawi were responsible. The Philippine military had wrested back the ruined city after a five-month battle against pro-Islamic-State foreign and local fighters in 2017. The regions affected by the attack are part of the Bangsamoro Autonomous Region in Muslim Mindanao, where the Muslim minority was given self-rule as part of efforts to prevent violent extremism. Manila had also signed a peace pact with the Moro Islamic Liberation Front in 2014, ending their armed rebellion.