Isis rivals Jaysh al-Islam 'turn militant group's tactics against them' in a mass execution video

Executors dressed up in the orange jumpsuits normally seen on Isis’s victims

Video posted by Jaysh al-Islam shows execution of up to 18 alleged Isis fighters

A rival jihadist group battling against Isis in Syria has released a copycat execution video in the style of the so-called “Islamic State” – but reportedly with Isis militants as the victims.

In what was claimed to be a role reversal after Isis publicly executed dozens of its own fighters, Jaysh al-Islam posted the video online showing the slaughter of up to 18 alleged members of the rival militant group.

The propaganda video is a clear attempt to mimic the now infamous style of Isis executions, but with Jaysh al-Islam’s own fighters dressed in the orange jumpsuits normally reserved for victims.

Men, who during the 19-minute video are claimed to be Isis fighters of various ranks, are led out in black clothes and masks, dragging ball-and-chains, before they are unmasked and shot at point-blank range with shotguns.

In the video, a Jaysh al-Islam fighter identifies Isis as “khawarij”, meaning “those who have transgressed” – the same term that Hamas uses to refer to the group.

“This group claimed to be the mother state and made Takfir [accused of apostasy] on other Muslims, shed their blood and looted their properties and dignities,” the fighter says before the executions are shown.

“This is the penalty for what they have committed. We also call on their fellows to repent.”

Both Isis and the smaller Jaysh al-Islam are fighting the government forces in Syria, but have also clashed with each other after the latter was formed out of around 60 rebel factions who refused to declare allegiance to Isis’s “caliphate”.

Previous images in a very different style from Jaysh al-Islam have boasted its military strength, and it is thought to command up to 25,000 fighters.

But far from a victory over Isis in Syria, the new video was viewed by experts as simply another jihadist movement “stooping to Isis’s level”.

Charlie Winter, an analyst with the counter-extremism think-tank Quilliam, said that the killings and recording were likely carried out a while ago and first appeared in trailers on 25 June.

“Even though the killing was done way back, there was doubt as to whether the video would be released,” he said. “Isis goaded Jaysh al-Islam into it.

“And, seeing Isis’s reaction on Twitter, it is so clear that this was the desired effect.”