At least 20 people have been killed and dozens more injured after two bombs exploded during Sunday Mass near a Roman Catholic cathedral in the Philippines island of Mindanao.

The first blast that took place outside Jolo cathedral was followed by a second explosion just after emergency services arrived at the scene to treat the wounded, security officials told AP. At least 20 people were killed and more than 70 others wounded in dual explosions, security officials said. According to unofficial reports, casualties included both troops and civilians.

Hindi bababa sa 15 ang patay sa naganap na pagsabog sa Jolo Cathedral sa Jolo, Sulu, ngayong umaga. @gmanews@gmanewsbreaking@dzbbpic.twitter.com/x7RoswlMKW — peewee bacuño (@hero_peewee) January 27, 2019

While no group has claimed responsibility for the attack, the Philippines armed forces have long been fighting Abu Sayyaf terrorists on the island of Mindanao. The Sunday morning explosions seem to resemble tactics previously used by the Islamic State-linked (IS, formerly ISIS) militant group to inflict mass casualties.

LOOK: Situational images after the explosion that happened at a cathedral in Jolo, Sulu this morning. @cnnphilippines(Photos: Amarkhan Jidara) pic.twitter.com/VSWTqBpm4O — Marlon Pañares 🇵🇭 (@marlon_gevity) January 27, 2019

JUST IN: Two explosions occurred in Jolo Cathedral, Jolo, Sulu at about 08:28AM. The explosive is still of unknown make and origin. Postblast investigation to be done. Suspects and motive to be identified and investigated. (1/2) pic.twitter.com/y6jTRm1tk2 — People's Television (@PTVph) January 27, 2019

Fearing further attacks on a turbulent island, Defense Secretary Delfin Lorenzana directed troops to secure “all places of worships and public places.”

The country’s officials pledged to “crush” those responsible for the bombings. “The Armed Forces of the Philippines will rise to the challenge and crush these godless criminals,” Philippines President Rodrigo Duterte’s spokesman, Salvador Panelo, said, according to local media.

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