The Sudan People’s Liberation Movement north said it clashed with governent forces in Blue Nile on saturday.
The SPLM-N killed 16 army soldiers in the Tivol area and five others in Mugum, said SPLM spokesman Arnu Ngutulu Lodi.
Lodi said the movement destroyed two armoured vehicles loaded with ammunition and seized a number of weapons.
The commssioner of humanitarian affairs has revealed that 500 families fled from Mugum into the surrounding areas after government forces allegedly burned down their villages.
Official of humanitarian affairs for Blue Nile state, Hashim Orta told Radio Tamazuj he was concerned over the fate of families caught up in the middle of fighting between the Sudanese army and SPLM forces.
He called for the international community and humanitarian organisations to pressure the government to open secure humanitarian corridors to provide urgently needed security and aid for these families.