"Rebels from the Sudan People's Liberation Army-North (SPLA-N) attacked nomadic herders on their migration route from the south to the north and soldiers securing a road, ambushing them and planting mines" in the South Kordofan region on Thursday, the statement said.

Asa a result there were a number of wounded and "many dead among civilians and security forces, while military equipment and (herders') belongings were destroyed," it added.

Violence is endemic between nomadic Arab tribes and farmers from African tribes in Sudan.

The SPLA-N blamed the incident on "a governmental militia".

"We reject this policy of the government that favours an Arab group over non-Arabs and we will not stand idly by if this continues," it said in a statement.

The clash came as peace negotiations are ongoing between the government and rebel groups to bring stability to the restive regions of Darfur, Blue Nile and South Kordofan.

For years rebels have accused the government of marginalising the regions and fought against the forces of former president Omar al-Bashir, who was ousted in April 2019 by the army under pressure from a mass protest movement.

A transitional government took office in August 2019, with Prime Minister Abdalla Hamdok making peace in the three regions a priority after long years of conflict in which hundreds of thousands of people died and millions were displaced.