MARAWI CITY- Desperate Maute extremists are using liquefied petroleum gas tanks and unexploded military ordnance to fight off advancing military troops, the Armed Forces of the Philippines said Friday.

Col. Romeo Brawner, deputy commander of Task Group Ranao, said Maute terrorists combine LPG with homemade bombs to make their own explosives.

"They used the unexploded ordnance. They rigged this to become IEDs (improvised explosive device) yun karamihan na-recover natin, but some are homemade," Brawner said.

Nearly 1,000 people, mostly terror suspects, have been killed in the battle in Marawi City, which began last May 23.

Government forces are targeting to finish the siege by October 15, Brawner said.

Around 80 buildings are still needed to be cleared by state forces with the main battle area reduced to only less than 3 hectares.

"Medyo nahi[hi]rapan forces in the sense that our enemy have dug themselves in trenches and occupied basements of buildings, even if we bomb them they still survive because they are safe underground," Brawner said.