The Philippines armed forces said there are now fewer than a hundred ISIL-allied fighters still holed up in the southern city of Marawi.
But at the height of the siege, their number might be around 700, including children.
There are some videos suggesting child combatants being trained. In a video, children can be seen being indoctrinated and trained to fight.
Abdul, a 17-year-old, has been fighting alongside the extremist. He joined when he was only 12. Abdul escaped from the group realizing militant recruiters lied.
Some terrorism experts and the military said the use of child soldiers by ISIL in the Philippines dated back to the days before they came to prominence.