At least four people were killed after an explosion occurred while Catholic Mass was going on inside the gymnasium of the Mindanao State University in the predominantly Islamic city of Marawi on Sunday (December 3).

Campus security chief Taha Mandangan said that the morning service was underway when the explosion happened, which caused panic among students, teachers, and others in the congregation.

Several people were also wounded, with at least six of them taken to hospital in critical condition, Lanao del Sur Governor Mamintal Adiong Jr. added.

Two of the deceased - a male and a female - have been identified, while the identities of two other women who died remain unknown.

"This is clearly an act of terrorism," Mandangan told the Associated Press. "It's not a simple feud between two people. A bomb will kill everybody around."

In its statement, the Mindanao State University "unequivocally" condemned the incident. They have also suspended all classes until further notice.

Military and police units have been tasked to cordon off the scene as investigations are underway.

Philippines: At Least 4 Dead in Explosion During Catholic Mass in Marawi
(Photo : MERLYN MANOS/AFP via Getty Images)

Christian Deaths in an Islamic City

Marawi is the capital of the province of Lanao del Sur and one of the major cities of the Bangsamoro region, which has a Muslim majority in a predominantly Roman Catholic nation. Christians in the region have been living in relative peace with Muslims in the area.

The city has since been on edge after Islamic State-affiliated local terrorists held the city back in 2017.

The blast, which was caused by an improvised explosive device later identified as a 60-millimeter mortar round, sparked a security alarm across the island of Mindanao, as well as other parts of the archipelago, including the capital Manila and regional centers Cebu and Davao, as the Christmas season kicked into overdrive.

Regional military commander Maj. Gen. Gabriel Viray III said that at least 50 people were taken to two hospitals in the area for emergency medical treatment.

Philippine military chief Gen. Romeo Brawner Jr. - a veteran commander of government forces in Marawi during the five-month-long battle in 2017 - added that the bomb attack could be retaliation by Muslim militants for a series of battle setbacks as state troops and police units in Mindanao have been flushing out Muslim extremists in the island.

Brawner further cited the killing of 11 suspected Islamic militants in a full-scale military offensive on Friday (December 1) in the province of Maguindanao.

Bangsamoro police chief Brig. Gen. Allan Nobleza added that the slain fighters belonged to Dawlah Islamiyah, an armed group affiliated with the Islamic State.

For its part, the Philippine Coast Guard said it would order its personnel to assist defense and public security forces by intensifying its intelligence gathering, stricter inspections of passenger ferries, and the deployment of bomb-sniffing dogs and sea marshals across the country's ports.

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Filipino Officials, Churchmen Condemn Killings

Meanwhile, authorities from both church and state have condemned the incident.

In a statement, Philippine President Ferdinand Marcos Jr. said he vehemently condemned the attack in the university, claiming that it was "perpetrated by foreign terrorists" without elaborating further.

"Extremists who wield violence against the innocent will always be regarded as enemies to our society," he added.

Defense Secretary Gilberto Teodoro later told a news conference that there was a strong indication of a "foreign element" in the bombing, but also did not make any elaborations.

Adiong said that his province has been advocating the promotion of basic human rights, including the right to religion, and that the attack being executed in a school only made it worse.

"I urge the security sector to get to the bottom of this immediately!" he added.

Provincial representative Zia Alonto Adiong also echoed the governor's remarks, adding that the province "[stands] in solidarity" with the Christian community of Marawi and the Bangsamoro region.

On the other hand, the Bishop of Caloocan, Pablo Virgilio David, issued a statement on behalf of the Catholic Bishops Conference of the Philippines (CBCP), saying that they were condemning the attack on the first Sunday of Advent, the first day of the Catholic liturgical year.

David stated that the attack also happened merely days after "Red Wednesday," a commemoration held by the Catholic Church every last Wednesday of November to remember Christians persecuted, harmed, or killed for their faith.

"Such violence should not only be denounced; it should also be renounced as a way of seeking redress by every peace-loving Filipino," he added.

In a separate statement, Filipino Cardinal Orlando Quevedo - whose final appointment prior to retirement was the archbishopric of Cotabato, also in Mindanao - said that the attack was a "crime that literally cries out to heaven." He also called on law enforcement agencies to hold the perpetrators accountable. He also recalled the bombing of Jolo Cathedral in the archipelago province of Sulu back in 2019.

The cardinal has been named a member of the council of leaders in the Bangsamoro region, Rappler reported.

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