LONDON • The Islamic State in Iraq and Syria (ISIS) has released a video showing five boys, including one it identifies as British, carrying out the killing of prisoners in Syria.

The boys look like they are about 10 to 13 years old. They are armed with pistols and wear military gear and black bandanas.

They stand behind the adult prisoners, who are kneeling, and shoot them.

The one whom the militant group claims is British is named as Abu Abdullah al-Britani, the Independent reported. It is a name used by several other British militants in the Middle East in the past, said the newspaper.

As the age of criminality in Britain is 10, the boy could face murder charges if he is brought back to the country, the report added.

ISIS also claims that the other four boys in the video are Egyptian, Kurdish, Tunisian and Uzbek nationals, according to Site Intel Group.

Known as "cubs of the Caliphate", more children are being used by ISIS as soldiers after the group was forced to retreat from major strongholds in Iraq and Syria, the Independent report said.

Children have featured prominently in ISIS propaganda in which the militant group boasts about preparing the next generation of fighters.

In February, the militant group released a video showing a British boy wearing an ISIS bandana and a camouflage outfit.

The boy, said to be aged under five, was allegedly the son of Grace "Khadija" Dare, a Muslim convert extremist from Lewisham in south-east London, the Independent reported.