Just a few dozen IS-linked fighters remain in troubled Philippines province

The number of Islamic State group-linked militants in the southern Philippines city of Marawi is down to around 20 to 40, the country's military said on Monday.

Despite its small number, the IS-inspired Maute militant group remains a threat to the country and fighters still hold hostages in two districts, army Spokesman Brig. Gen. Restituto Padilla warned.

"Based on the ground commander's estimate, their number has decreased to less than 40. So maybe their forces have been reduced to between 20 and 40. The force is getting smaller," Padilla told reporters at the presidential palace in Manila.

"Their capacity to inflict harm, by the way, is still there because they still have arms, they still have adequate ammunition and they still continue to hold hostages. So that's the compounding factor," he added. 

Marawi City, which has a predominantly Muslim population, was besieged by Maute group militants in May, leading to Philippine President Rodrigo Duterte to declare martial law on the entire island of Mindanao.

Army spokesman Padilla said in Monday's press conference that the defeat of Maute in Marawi would not necessarily mean the end of martial law.

"Actually, don't look at Marawi per se as the reason for keeping martial law. You know this rebel group has a structure that is beyond Marawi. They have groups in other portions of Lanao, in Maguindanao, in Sulu archipelago," he said.

Since May, a total of 562 militants and 128 government troops have been killed in ongoing clashes. The battles have also claimed the lives of 45 civilians and displaced over 467,000 people.

In recent days, reports have also emerged of the Maute group using hostages as suicide bombers and calling for reinforcements - matters which the Philippines government said it is investigating.