Fears are mounting of mass killings in the key Sudanese city of el-Fasher after the paramilitary Rapid Support Forces (RSF) captured it from government forces, BBC reported.

In a address on Monday evening, Sudan's military chief Gen Abdel Fattah al-Burhan said he had approved the withdrawal of troops in response to the "systematic destruction and killing of civilians".

The UN said there were credible reports of "summary executions", while Yale University's Humanitarian Research Lab referred to satellite imagery of "piles of bodies executed en masse".

The RSF has denied accusations of killing civilians and targeting non-Arab ethnic groups, despite evidence presented by the UN and human rights organisations, according to BBC.