The Islamic State reportedly claimed responsibility for the double-bombing of a Catholic Church in the Philippines on Sunday. The attack left at least 20 dead, 15 of which were civilians and 5 were soldiers, according to multiple reports. In addition to the 20 killed in the attack, 111 people were reportedly injured, 90 of which were civilians.

The attack occurred at the Cathedral of Our Lady of Mount Carmel in Jolo, Sulu province. The SITE Intelligence Group, who monitors the online activity of ISIS, said that the terror organization claimed responsibility for the attacks on their propaganda outlet the Amaq News Agency.

The Associated Press reported:

The first blast sent people, some of them wounded, fleeing out the church’s main door. Army troops and police were rushing inside when the second bomb exploded a minute later. The explosions scattered wooden pews inside the main hall, blasted out window glass panels and hurled human remains and debris across a town square fronting the Cathedral of Our Lady of Mount Carmel, witnesses said.

The military is investigating a report that the second bomb may have been connected to a parked motorcycle near the church. (RELATED: Here’s Why The Texas School Shooter Says He decided To Join ISIS)

Some casualties were transported from the scene by vehicle and brought to a local hospital, while others were evacuated by air transport and brought to a healthcare facility in Zamboanga city, which is not far from the scene of the attack.

Defense Secretary Delfin Lorenzana reportedly made efforts to mobilize law enforcement and military forces to secure other places of worship following the attack.

“I have directed our troops to heighten their alert level, secure all places of worships and public places at once, and initiate pro-active security measures to thwart hostile plans,” Lorenzana said, according to Fox News.

Lorenzana reportedly identified Hatib Sawadjaan, commander of the Abu Sayyaf group and self proclaimed member of ISIS, as being responsible for the attack. (RELATED: US Drone Strikes Kill Afghan ISIS Leader)

The office of President Rodrigo Duterte made a statement in the country’s capital, Manila, promising pursuit of the ISIS terrorist responsible.

“We will pursue to the ends of the earth the ruthless perpetrators behind this dastardly crime until every killer is brought to justice and put behind bars. The law will give them no mercy,” the statement said. “The enemies of the state boldly challenged the government’s capability to secure the safety of citizens in that region. The (Armed Forces of the Philippines) will rise to the challenge and crush these godless criminals.”

The attack occurs almost a week after minority Muslims in the largely Roman Catholic country supported the establishment of an autonomous region in the southern Philippines, in hopes of bringing peace to a nearly five-decade period of violent separatist movements that have cost approximately 150,000 lives. Most Muslims in the Philippines voted in support of the region’s establishment. Many voters in the Sulu province, however, rejected the proposal. The Sulu province is home to a rival militant rebel faction that has not participated in peace processes and is opposed to the agreement.