At least four people were killed and dozens of others injured on Sunday in an explosion at a Roman Catholic Mass inside a university gymnasium in the southern Philippine city of Marawi, officials said.
The Islamic State later claimed responsibility for the attack, according to Site Intelligence Group.
The blast, thought to be caused by a grenade or a homemade bomb, ripped through a gymnasium at Mindanao State University. The university, in Lanao del Sur Province, was at the center of fighting in 2017 that displaced more than 100,000 people, after local and foreign Islamic State militants laid siege to Marawi.
At least 1,200 militants, government forces and civilians were killed during those battles, which lasted for five months. Parts of Marawi, in the region with the country’s biggest Muslim population, remain off limits to civilians because there are still unexploded ordnance from the conflict.
The Amai Pakpak Medical Center in Marawi, to which all of the casualties were rushed, said that four people had died on the spot and that seven others were seriously injured. About 40 others were released after being treated for their wounds, said the hospital, which had said earlier that 11 had died in the blast.
Maj. Gen. Gabriel Viray III, the commander of the First Infantry Division in the area, said an investigation was underway to determine whether the local Islamic state affiliate, known as the Daulah Islamiyah-Maute Group, was responsible. (Daulah Islamiyah means “Islamic State” in the local language.)
“We are looking at the bomb signature and trying to determine if it’s them,” he said.
Gen. Romeo Brawner Jr., the armed forces’ chief of staff, said the attack might have been in response to a clash on Friday that left 11 militants from the local Daulah Islamiyah cell dead in the province of Maguindanao, also in the south.
Additionally on Saturday, he said, government forces staged an operation that killed Mudzimar Sawadjaan, alias Mundi, a senior leader of another group, Abu Sayyaf, that had also pledged allegiance to the Islamic State.
“We are looking at the angle that the bombing this morning might be a retaliatory attack,” General Brawner said.
The nation’s defense secretary, Gilberto Teodoro, said that President Ferdinand Marcos Jr. had directed the military and the police “to conduct a swift and thorough investigation of the incident.”
For his part, President Marcos assured the public in a statement that “the perpetrators of this senseless act” would be brought to justice, and he promised that additional troops would be deployed to the area and swift government aid given to victims and their families.