Shocking new footage released by ISIS’ propaganda machine appears to show five children — one of whom is thought to be British — executing captives.

The video is believed to have been recorded in the de facto ISIS capital of Raqqa, a city in Syria, according to SITE intelligence group.

Warning: This video contains graphic content

It features five child executioners in total, all wielding pistols and wearing the desert camouflage common among ISIS fighters.

One of the youths shouts out in Arabic before they raise their handguns and kill the men in front of them.

The reportedly British child, second from the right, is believed to be called Abu Abdullah Al-Britani, though this has yet to be officially confirmed.

He shares the name with another Brit who fought for ISIS.

The other Al-Britani was the Islamic name of Assad Uzzaman, originally from Portsmouth, who was 25 when he was killed in Syria last year.

Included with the British child are kids believed to be of Egyptian, Kurdish, Tunisian and Uzbek background.

The inclusion of children from many backgrounds is a common theme in ISIS propaganda, as the group likes to point out its international presence in an apparent attempt to gain legitimacy.

ISIS has encouraged the training of “Cubs of the Caliphate” since it began its rise in Iraq and Syria in 2014.

It’s understood children as young as 10 are put through rigorous military training and indoctrination. Propaganda videos depicting the training show the children learning how to take hostages, operate as snipers and engage in ambushes. One particularly horrific video released in July last year depicted children executing 25 Syrian soldiers.

While the deplorable act of using child soldiers is hardly a new concept in the ISIS ranks, it’s believed this may be the first time a child from a Western country has been featured.

British Foreign Secretary Philip Hammond admitted in January that around 1,500 British people have attempted to join ISIS and other terrorist organisations in Syria.