The 22-minute video posted on jehadist forums, which included both new and previously released footage, shows hundreds of executions, providing further evidence of the scope of the atrocity.Some of the victims are shown pleading for their lives, attempting to explain they had only just joined the security forces. The grisly footage shows executions on an industrial scale, with victims falling out of dump trucks and later lying side by side in shallow mass graves before being shot dead one by one.