A video released by the Islamic State group Tuesday appears to show a young child soldier executing two Russian security agents. The video, released by the militant group’s official media wing, Al Hayat Media, shows the boy targeting captured agents of Russia’s Federal Security Service (FSB), reported Agence France-Presse. The child, who appears to be about 10, has previously been featured in a November propaganda film depicting the training of child soldiers by the militants also known as ISIS in Kazakhstan.

The new video showed the FSB captives being interviewed before their execution, according to Vocativ, which summarized the video’s contents. One of the agents identified himself as Mamayev Jambulat, a Kazakh national, and claimed that he had been sent to gather information about the terror group and to get closer to one of its members. The other agent, identified on the video as Sergey Nikolayavich, said he had previously worked in Russian intelligence, which paid him for each piece of information he was able to obtain from the group. The man identified as Nikolayavich also said he had been sent to locate and assassinate a senior ISIS leader.

After the interviews with the captives, the video cut to an adult ISIS fighter in military clothing standing next to the child soldier, who was holding a pistol. The adult soldier then recited verses from the Quran and said the two captives were “in the custody of the lion cubs” of ISIS. The end of the video featured the boy stepping forward and shooting each man in the head and then several times after they collapsed.

In the earlier propaganda video featuring child soldiers, the same boy said he wanted to grow up and kill “infidels.” In that video he identified himself as Abdallah and said he was from Kazakhstan, said AFP.

Experts have suggested that the increasing use of children in ISIS propaganda films represents a departure from the group’s already brutal methods. “Whether it is real or staged, [ISIS] used a young child in this video for the shock factor, and the shock factor alone,” said Charlie Winter, a researcher for the anti-extremism think-tank Quilliam, according to the Independent of London. “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.”

Some have cast doubt on the video, however. "There are a lot of things that don't sit right with me,” military expert Will Geddes told the UK’s Mirror. "You see a shell casing ejected from the Glock and you see the impact on the guy's shoulder, but you would get that from a blank. There is no blood and at that close range there would be an exit wound,” he said.