The video, released through Isis’s official propaganda outlet al-Hayat Media, shows two men who it claims are “agents recruited by Russian intelligence” apparently being shot in the desert by a child who is thought to be around 10 years old.
It comes just a day after another video showed a child aged around 14 apparently carrying out a suicide bombing in the Iraqi province of Salahuddin.
A previous video showed a young boy who Isis claimed took part in a suicide bombing
And while the apparent execution could not be independently verified, experts suggested that the increased use of children in the atrocities it films represented “a departure from past norms”, even by Isis standards.
The new video is entitled “Uncovering an enemy within”, and has been published by the branch of Isis which specialises in making propaganda videos for an international audience.
Including captions in Arabic and English, it claims the two men are “FSB agents”, offered money to “gather information about fighters and send the information to Russia”.
After they are shown “confessing” to the camera, a separate part of the video shows the two men on their knees in the desert before a militant and a boy who can be no more than 10 years old.
The militant says the men are now “in the custody of the lion cubs of the caliphate”, before the child steps forward and appears to shoot the men.
The same child has appeared in previous Isis videos, and also features in a clip at the end of the most recent video that appears to have been shot some time earlier.
Charlie Winter, a researcher for the anti-extremism thinktank Quilliam, said: “Whether it is real or staged, [Isis] used a young child in this video for the shock factor, and the shock factor alone.
“Its propagandists have done it before – showing images of children training as soldiers and being kicked in the stomach in martial arts drills – but this latest video marks a departure from past norms.”
The video comes amid increased speculation over the blurring of lines between disparate militant groups like Isis and al-Qaeda in the Arabian Peninsula (AQAP), particularly in the wake of the Paris shootings.
And while many social media users speculated as to whether the apparent execution was genuine, Isis supporters shared it as a warning to “you who sent spies”.
One Isis-affiliated account under the name Abu Marthad al-Muhajir tweeted: “This is not al-Qaeda, this is the Islamic State, O you filthy stupid Marxists of Russia. This is your destiny.”