Sudan's Rapid Support Forces (RSF), which have been battling the country's army for two years now, have been accused of committing major atrocities during the capture of the western Sudanese city of el-Fasher after an 18-month siege.

Joint Forces, a group allied with the Sudanese army, said Tuesday that the RSF had, "committed heinous crimes against innocent civilians in the city of el-Fasher, where more than 2,000 unarmed citizens were executed and killed on October 26 and 27, most of them women, children and the elderly."

The Sudanese army confirmed that its forces had withdrawn from el-Fasher after concluding that a retreat was necessary "given the destruction and intentional killing of civilians," with the UN adding, "risk of further large-scale, ethnically-motivated violations and atrocities in el-Fasher is mounting by the day."

With el-Fasher, the RSF now holds almost the entirety of western Sudan under its control.

African Union condemns 'atrocities'

On Tuesday, African Union Commission Chairman Mahmoud Ali Youssouf took to X to, express "deep concern over the escalating violence and reported atrocities in el-Fasher."

Youssouf's statement condemned "alleged war crimes and ethnically targeted killings of civilians." In it, he called for an "immediate cessation of hostilities and the opening of humanitarian corridors to allow life-saving aid to reach affected populations."

Youssouf made clear there could be "no military solution" to the crisis in Sudan before urging parties to engage in dialogue to "commit to a peaceful, inclusive political process."

Observers say the capture of el-Fasher in western Darfur could mark a turning point in Sudan's ongoing conflict, which has killed tens of thousands of people and displaced nearly 12 million.

RSF gains could cement partition

The RSF has established Darfur region as its stronghold with top RSF leaders like General Mohamed Hamdan Dagalo, known as Hemedti, based there.

Analysts say the latest RSF gains could hasten the partition of Sudan, pointing to recent history in Libya as a possible template for a situation in which rival militia linked to rival governments oversee an uneasy break-up and coexistence.

Edited by: Kieran Burke