An unknown number of casualties have been reported following clashes between military forces and armed groups at the facilities of a former international peacekeeping mission in Sudan's Darfur region on Saturday, a military statement said.

Witnesses told Reuters they had heard heavy gunfire on Saturday around the perimeter of the headquarters of the former African Union-United Nations peacekeeping mission UNAMID in el-Fasher, North Darfur, but said the number of casualties was unclear.

There has been a surge in violence and displacement in Darfur since 2020 that analysts have linked to factions jostling for power around a peace deal signed with some former rebel groups that year, and UNAMID's ceasing operations at the start of 2021.

Sudan's military leaders said on Wednesday the groups that signed the deal would have to leave cities in Darfur following looting and attacks that led the U.N.'s World Food Programme to temporarily suspend its operations in the region.

The UNAMID peacekeepers were meant to be replaced by a national joint force that is yet to be deployed. Former UNAMID facilities have been repeatedly attacked and looted.

Conflict that escalated in Darfur from 2003 killed an estimated 300,000 people, as government forces and allied militias sought to crush a rebellion. Some 2.5 million people live in displacement camps in Darfur.