Extensive areas of the mostly Muslim city on the island of Mindanao were seized by Islamist fighters on May 23 in the aim of creating a region run by the extremist cult.
The UN children’s agency Unicef said there was “little known first-hand information about the situation inside the city due to limited access”.
The organisation has begun stockpiling and funding to provide essential support for water, sanitation and hygiene for refugees but said “there are still significant gaps to meet the needs of the displaced population”.
More than 100 combatants reportedly remain in the city despite concerted military efforts to defeat them.
Teenagers are thought to be among them, a military spokesman said.
Brigadier General Restituto Padilla told the media in Manila: “We continuously get disturbing narratives from [refugees] that children as well as hostages are being employed in the firefight.
“As disturbing as it is, our troops are doing their best to avoid any casualty among these children that are being employed,” the brigadier said.
“But in the event… they bear arms and are involved in the fighting, there is nothing much that we can do. Similar to the hostages who are being forced.”
Manila claims that civilians have been forced to carry supplies and ammunition for the militants and that more than 500 people had been killed in the fighting, including 89 soldiers and police, 39 civilians and an estimated 379 militants.
Around 400,000 civilians have left their homes and the centre of Marawi has been hit by regular air bombardment.
The Philippines’ bishops have called for an end to the clashes in Marawi and condemned the “violent extremists”.
Lingayen Archbishop Socrates Villegas: “We all cry from our hearts: war in Marawi, never again! War in Marawi, no more! We therefore call for the return to normalcy and peace in Marawi and its environs as soon as possible.”
Villegas has also criticised several of President Rodrigo Duterte’s policies, including his unrestricted war on drugs. He has also expressed doubts about whether the extension of martial law in Mindanao would end the crisis in Marawi.
Fighting continues in Marawi. Picture credit: YouTube