At least four people were killed while scores were injured when a suspected improvised explosive device (IED) went off at a school gymnasium in Marawi City on Sunday, Dec. 3, in what the military described as the most violent attack in the Islamic City since the Marawi siege in 2017.
The explosion occurred at the Dimaporo Gymnasium inside the Mindanao State University (MSU) while there was an ongoing Advent mass for worshipping Christians around 7 a.m., said Major General Gabriel Viray III, commander of the 1st Infantry Division (1ID).
"While nasa first day of Advent mass sa Marawi sa loob ng Dimaporo Gymnasium, doon may sumabog (An explosion occurred on the first day of Advent mass inside the Dimpaoro Gymnasium in Marawi)," Viray said.
Three females and one male mass attendees were immediately killed in the incident while at least 50 others were injured - 42 were brought to Amai Pakpak Medical Center while eight were rushed to the MSU Infirmary.
Viray said the military have yet to identify the perpetrators behind the explosion but they were looking at a possible retaliation by the Islamic State (IS)-linked Daulah Islamiyah (DI) - Maute Group as among the possible angles.
"Wala pa tayong ano but this is a terror act probably [by] the Daulah Islamiyah-Maute Group kasi nasa Lanao del Sur. Tinitingnan pa natin yung signature bomb kung indeed sila (We have no [suspects] yet but this is a terror act probably [by] the Daulah Islamiyah-Maute Group because they are in Lanao del Sur. We are looking at the signature bomb if they are indeed the culprits)," he said.
"As far as I know, this is probably the [most violent attack] since the Marawi siege," the commander added, referring to the foiled attempt by terrorist and extremist groups led by the Maute Group to establish a caliphate of the Islamic State in Marawi City in May 2017. The five-month crisis resulted to the death of 978 terrorists, 168 government troops, and 87 civilians as well as the wounding of 1,400 individuals.
Prior to the incident, the 6th Infantry Division (6ID) also launched airstrikes and ground assault against Daulah Islamiyah in Datu Hoffer Ampatauan, Maguindanao del Sur last Dec. 1 which led to the death of 11 militants.
The military also encountered Daulah Islamiyah militants in Piagapo, Lanao del Sur on Sunday morning, killing one of its sub-leaders, but further details of the operation have yet to be available, according to Viray.
The military in Marawi City was placed on a heightened alert following the explosion. From 100 Daulah Islamiyah militants, Viray said the group's strength has been reduced to 41 fighters still operating in Lanao del Sur.
"Right now, we are on a heightened alert and our troops remain vigilant. We are determining the motive behind this incident and the perpetrators," he stated.
The Philippine Coast Guard (PCG) also placed all Coast Guard Districts on a heightened alert due to the incident.
PCG Commandant, Admiral Ronnie Gil Gavan directed the PCG district commanders in Mindanao to intensify pre-departure inspection of ships, K9 inspections, deployment of sea marshals and coastal security patrols to ensure the safety of the seagoing public and the maritime industry.
He also directed the officials on the ground to collaborate with the police, military, and local government officials in the conduct of intelligence gathering which could lead to the arrest of the suspects.