A chilling new video from ISIS shows a British boy and four other children executing prisoners in cold blood in Syria.
The grotesque nine-minute video is believed to have been recorded recently in the ISIS capital of Raqqa, in Syria, and shows the organisation is becoming even more brutal as it retreats into its heartland.
The video shows five boys - believed to be from Britain, Egypt, Turkey, Tunisia and Uzbekistan, wielding handguns and wearing the desert camouflage.
One of the youngsters makes a blood-curdling shriek in Arabic and slaps one of the terrified captives on his shaved head before they raise their guns and kill the five men, thought to be Kurdish fighters who were captured during a battle.
The Sun reported the British boy was identified only as Abu Abdullah al-Britani.
He is white, blue-eyed and aged around 12.
He and the other children copy five older jihadists who execute prisoners in orange jumpsuits and butcher them with knives.
The age of criminal responsibility in Britain is 10 so if the boy was captured and sent back to Britain to face justice he could be prosecuted for murder.
Dozens of British jihadists are believed to be fighting for ISIS in Syria and Iraq under the nom de guerre al-Britani, which simply means British in Arabic.
Last year Assad Uzzaman, 25, from Portsmouth, was killed in Syria while using the name al-Britani.
ISIS has been increasingly using child soldiers - known as the 'Cubs of the Caliphate' amid speculation it is running low on manpower as it retreats from positions in Syria and Iraq and falls back on its stronghold, around Raqqa.
The Quilliam Foundation reported this year that around 50 British children are 'growing up on jihad' and being groomed to become ISIS fighters.