IS buried thousands in 72 mass graves

Surrounded by smoke and flames, the sound of gunshots echoing around him, the young man crouched in the creek for hours, listening to the men in his family die.

On the other side of the mountain, another survivor peered through binoculars as the handcuffed men of neighboring villages were shot and then buried by a waiting bulldozer. For six days he watched as the extremists filled one grave after another with his friends and relatives.

Between them, the two scenes of horror on Sinjar mountain contain six burial sites and the bodies of more than 100 people, just a small fraction of the mass graves Islamic State extremists have scattered across Iraq and Syria.