Executioner dressed in orange jumpsuits - attire usually worn by ISIS's victims - the Jaysh Al-Islam soldiers lead 13 shackled ISIS terrorist to their deaths.

So-called “Islamic State”'s captured terrorists are forced to kneel as a commander announces: 'Allah did not make a disease without appointing a remedy to it.'

The Jaysh Al-Islam member - dressed entirely in black - are then given something to drink before each of their faces are clearly shown in the 19 minute-long propaganda video. They are then shot in the back of the head at point blank range with shotguns.

Jaysh Al-Islam battle against President Bashar Al-Assad government and Syrian army is reportedly funded by the wealthy nation of Saudi Arabia.