The charred remains of 53 bodies were discovered in a warehouse in Tripoli on Sunday.

Local residents accused Gaddafi's most feared military unit, the Khamis Brigade, loyal to Gaddafi's youngest son, of the massacre. The residents reported hearing shooting several days prior. However, when they demanded answers, Gaddafi's forces threatened to kill them if they did not retreat.

The simmering remains were found by residents and rebel forces, once they captured the southern area of the city.

One man who claimed to have escaped the massacre said Gaddafi's forces had used the warehouse to execute those who refused to kill civilians.

However claims of rebel forces taking revenge on Gaddafi fighters, particularly those deemed to be mercenaries, distinguishable by their darker skin tone, have emerged.

Witnesses described finding bodies on their knees with their hands tied behind their backs, clothed in the charred remains of Gaddafi's military garb.

The gruesome discovery comes one day after 120 bodies were found in a Tripoli hospital. The hospital staff had evacuated as Gaddafi's forces began targeting the hospital. The patients however, with no where to go, kept coming.

The stench of blood and decomposing corpses has been described as unbearable.

See footage of BBC's John Simpson reporting from the hospital here.

These scenes of horror have added weight to the calls for an investigation into war crimes in Libya.