A Syrian rebel group has released an execution video showing the killing of 18 Isis fighters
A Syrian rebel group has released an execution video showing the killing of 18 Isis fighters.Video Grab/YouTube

A Syrian rebel group -- Jaish al-Islam, whose three fighters were beheaded by the Islamic State terrorists recently -- has released a video showing the execution of 18 Isis fighters.

Jaish al-Islam is a major rebel groups primarily based in the Ghouta region of Damascus and has an army of some 25,000 soldiers. Since the beheading of its three fighters, a reprisal of sorts was expected.

In the video, the 18 Isis prisoners are seen in black dress, while the fighters of Jaish al-Islam (Army of Islam) sport orange clothes.

The Isis prisoners are then made to walk to the execution site wearing chains on their hands and ankles with metal  balls attached to them.

The nearly 20-minute video ends with Jaish al-Islam fighters executing all 18 Isis men by shooting them in the head from a point blank range using shotguns and assault rifles.

Before executing the men, one of the Jaish fighter calls Isis "dogs of hell" and "Khawarij". He then adds: "The most serious calamity of jihad today is a group of people who grow at a time of division among Muslims."

The Jaish fighters also accused Isis of shedding Muslim blood and striking deals with the Syrian army under president Bashar al-Assad. 

The copycat execution video is shot from several angles and bears stark resemblance to the Isis execution videos. The Times of Israel observed that the execution of 18 Isis fighters even contains similar sound effects and visuals similar to the Isis execution videos. 

According to the Middle East Eye, there have been several reports that there is "a cooperation - both tacit and direct- between the Syrian army and Isis".