The grisly footage shows executions on an industrial scale, as young men are seen falling from trucks and pleading for their lives before being lay down in shallow graves and sprayed with bullets.
Others are shot individually and their bodies dumped into the Tigris River, while an excavator is seen shifting vast piles of bodies as the executions continue into the night.
The footage reveals the true scale of last year's Speicher massacre, in Tikrit, Iraq, where up to 1,700 military cadets are thought to have been slaughtered, Mail Online reports.