The Maute group had established a stronghold in Lanao del Sur since February 2016 .
The Maute group was blamed for the 2016 Davao City bombing and two attacks in Butig , Lanao del Sur , a town located south of Marawi , in 2016 .
The Maute group had established a stronghold in Lanao del Sur since February 2016 and was blamed for the 2016 Davao City bombing and two attacks in Butig , Lanao del Sur , a town located south of Marawi , in 2016 .