Rebels in Sudan's Blue Nile state on Sunday claimed to have killed dozens of soldiers and disabled a tank during battle, but the military said it was the victor.

The Sudan People's Liberation Army-North said it "managed to destroy" a government convoy at Malkan on Friday.

Insurgents seized two other tanks in good condition along with long-range artillery pieces and various weapons, a rebel statement said, disputing government claims to have occupied the Malkan area.

Sudan Armed Forces spokesman Sawarmi Khaled Saad told AFP the battle in the southern Ingessana Hills had occurred 10 days ago, when Khartoum's forces defeated the rebels.

Access to the war zone is restricted, making verification of claims difficult.

Ethnic insurgents from the SPLA-N have been fighting since September 2011 in Blue Nile. A more intense war broke out earlier that year between the rebel group and government forces in South Kordofan state.

The unrest is fuelled by accusations of political and economic neglect.

Defence Minister Abdelrahim Mohammed Hussein said in November an operation had begun to crush the rebels.

More than one million people have been severely affected or displaced by the fighting in South Kordofan and Blue Nile, the UN says.