Military airstrikes in Marawi City began just before 6 am on Thursday.
At noon time, the air assets of the Armed Forces of the Philippines (AFP) are hovering over the conflict-torn city, indicating that bombardments targetting the positions of Maute group may happen anytime.
About 500 civilians remain trapped there.
The AFP says, Marawi City Hall cannot yet be used for any official function because building is still being continuously hit by bullets from Maute hideouts that are just about 200 meters away.
Lieutenant Colonel Christopher Tampus of the First Infantry Battalion says, soldiers have observed that the Maute terrorists would force their hostages to wear black suits so that government forces would mistake them for terrorists.
Tampus reports, the Maute terrorists continue to use their hostages as human shields.
It has been 31 days since the siege in Marawi started.
The heavy firefights have claimed the lives of 26 civilians and 65 government troops.
258 Maute terrorists have been killed.