Warning: This story contains graphic descriptions of executions.

Fighters laugh as they ride on the back of a pick-up truck, speeding past a row of nine dead bodies and driving towards the setting Sudanese sun.

"Look at all this work. Look at this genocide," one cheers.

He smiles as he turns the camera on himself and his fellow fighters, their Rapid Support Forces (RSF) badges on display: "They will all die like this."

The men are celebrating a massacre that humanitarian officials fear killed more than 2,000 people in the Sudanese city of el-Fasher last month. On Monday, the International Criminal Court (ICC) said it was investigating whether the paramilitary may have committed "war crimes and crimes against humanity".