The Maute group , an ISIS-inspired terrorist group , had reportedly been able to establish a stronghold in Lanao del Sur since early 2016 . The group had been blamed for the 2016 Davao City bombing and two attacks in Butig , Lanao del Sur , a town located south of Marawi , in 2016 . Before the Duterte administration , the Philippine government had downplayed the threat of ISIS in the Philippines . Even after the February 2016 Butig clash with the Maute group , then-President Benigno Aquino III discounted the possibility of the Islamic State 's presence in the country . He said that those behind the attack were just mercenaries wanting to be recognized by the Middle East-based terror group
2016 Davao City bombing
2016 Davao City bombing
Rodrigo Duterte