SUNDAY TIMES WEB DESK: The blast tore through the building as the victims were sleeping in the predawn darkness on the insurgency-plagued island of Mindanao, which is home to the Philippines’ Muslim minority.

Blood-streaked prayer mats and shattered glass could be seen on the floor inside the mosque where heavily armed security forces were standing guard, footage from the scene showed.

The blast came as the Catholic-majority nation was on high alert after a cathedral bombing claimed 21 lives at Sunday mass in an assault claimed by the militant Islamic State group.

Two people were killed and four others wounded in the mosque attack in Zamboanga City, authorities said, adding they had no indication so far it was retaliation for the cathedral bombing.