Filmed in a remote part of Deir ezzor province in Syria, the sickening video shows six recruits running through an historic ruins searching for the hidden prisoners.

With their hands tied behind their back, the captives are forced to wait as the young children, who appear to be no older than eight, use a pistol to kill them at close range.

The children involved in the horrific attacks appear to come from as far as North Africa and Tajikistan.

One after the other, the recruits run up the hill where they meet their instructor at the entrance of the historic al-Rahba castle.

They are handed a balaklava and handgun before they are told to enter the labyrinth of corridors inside the ruin, where they must search for the hidden prisoner.

Inside the dimly lit site, the child soldiers runs around before they find their helpless captive and execute them from close range.

One after the other, the children run up the hill where they meet their instructor at the entrance of an historic ruin

The prisoners are accused of spying in the ISIS held city of Deir ezzor, situated in eastern Syria.

After finishing the task, the child soldiers return to their instructor and hand the balaklava and handgun to next boy.

Each time, the prisoners are found in different locations and have no chance to escape. One of the victims is beheaded at the end of the video.

The child soldiers are also shown alongside a large group of children learning about close combat and self defence.