The Islamic State (Isis) has reportedly released a new video on Sunday (8 January), which showed three child soldiers — including a four-year-old — brutally killing three young men in Syria's northeastern Deir ez-Zor city.

The video also apparently showed them shouting "Allahu Akbar" after killing the men accused of spying for Kurdish Peshmerga forces, who are fighting with Syrian Democratic Forces (SDF) against the so-called Islamic caliphate established by the militants in the country.

IBTimes UK could not independently verify the authenticity of the video.

The child soldiers, or "Cubs of the Caliphate" as they are referred to by the militant group, carried out the executions on the orders of senior IS (Daesh) leaders, Ara News reported, adding that the video was released by the IS media office of Deir ez-Zor.

The propaganda video, shot in some deserted playground in rural Deir ez-Zor, first showed the three men confessing that they had been spying for the Kurdish YPG (People's Protection Units) troops. It then focused on Abu Mouaz al-Shami, a nine-year-old "Cubs of the Caliphate" member, who beheaded one of the victims with a knife and shouted "Allahu Akbar".

Next, the video showed Khattab al-Kamishli, 13, beheading another man. Facing the camera, the child soldier said his brother was killed by the Kurdish troops and "beheading this spy" was his revenge.

ISis child soldiers
Islamic State (Isis) reportedly released a new video on Sunday, 8 January, showing three child soldiers, including a four-year-old, executing three men for allegedly spying for Kurdish YPG forces in Syria's Deir ez-Zor city - File photo Twitter: @Terror_Monitor

The shocking moment featured next when the four-year-old shot the third alleged spy in the head and shouted "Allahu Akbar".

Omar Abu Laila, director of the Deir ez-Zor 24 activist network, told ARA News that the militant group brainwashed these children into killing others.

He added: "Isis has been kidnapping children and forcing them to join jihadist training camps in Raqqa, Deir ez-Zor and Mosul. They've been forced into committing such atrocities on behalf of the Isis self-proclaimed Caliphate."

The terrorist group is accused of forcing young children into fighting on the pretext of "Islamic Sharia", despite parents' oppositions and protests. The jihadist group reportedly takes away children from their parents, radicalises them and then provides military training before sending them off to different parts of IS-held territories to carry out atrocities and killings.