KHARTOUM -A prominent Sudanese rebel group has released 127 prisoners it had captured in fighting with government forces, most of them soldiers, the military said on Sunday.

The rebel Sudan People's Liberation Movement-North (SPLM-N) had captured the prisoners in Blue Nile and South Kordofan states, where the group has been fighting Sudanese government forces for years.

The released prisoners include 109 soldiers and 18 civilians, army spokesman Brigadier Ahmed Khalifa al-Shami said in a statement.

"The Sudanese army recognises this as a positive step towards achieving peace in the country," he said.

Ethnic minority rebels in Blue Nile and South Kordofan have been fighting government forces since 2011, accusing President Omar al-Bashir's Arab-dominated government of politically and economically marginalising the two regions.

Fighting in the two areas and in Darfur have left tens of thousands of people dead and displaced millions.

Khartoum announced a unilateral ceasefire in June 2016 in all three conflict zones, which it extended by six months in January.

UN officials say that for years Blue Nile and South Kordofan have been no-go areas for aid officials, leaving thousands of people without access to humanitarian relief.