The Philippine Catholic Church has confirmed that a priest and a number of church supporters were taken hostage by gunmen in the southern part of the city, The Australian reported.
There were reports that the militants had links to ISIS.
Philippine President Rodrigo Duterte announced the application of martial law in the southern province of Mindanao, pledging to react violently against the militants of ISIS after their attack on Marawi and raising a black flag on the city hall.