Security forces had killed at least 11 foreign militants along with over 600 members of the Maute group in fierce clashes in Marawi City, officials said Monday.

Rear Admiral Rene Medina, commander of the Naval Forces in Western Mindanao, said some 150 soldiers have been killed since the fighting started on May 23 when the Maute terrorists occupied Marawi in their bid to declare the city a province of the Islamic State (IS).