Sudan's army said it repulsed a rebel attack on its positions in South Kordofan state, killing 50 fighters, according to a statement from the military released late on Friday.
The army said the fighting took place about 15 kilometres south of Kadugli, the state's capital. Government troops were also killed and injured, although the army gave no further details.
The Sudan Tribune newspaper said the SPLM-N rebel grouping was unable to comment on the army's statement.
Sudanese troops have been fighting rebels in the state for over a year. South Kordofan borders South Sudan, which broke away from Sudan in 2011 to become an independent state after decades of civil war.
Khartoum accuses Juba of aiding the rebels who are seeking to overthrow the Sudanese government and have entered into an alliance with other rebel groups based out of the volatile western Darfur region.