Sudan's president has called a two-week, unilateral cease-fire in Southern Kordofan state, where government forces are accused of committing atrocities against civilians.

Speaking Tuesday in Kadugli, capital of the border state, President Omar al-Bashir said the situation on the ground would be assessed after the truce.

U.N. agencies are due to begin a fact-finding mission to Southern Kordofan on Saturday. Khartoum organized the mission after the U.N. human rights office said it had reports of indiscriminate killings, widespread looting and massive civilian displacement in Southern Kordofan, which borders the new state of South Sudan.

Sudan has rejected calls for an investigation by the U.N. rights office, which said most of the violent incidents were linked to Sudan's army, police and allied militias.

Fighting between government forces and Southern Kordofan's ethnic Nuba rebels broke out in June, about a month before South Sudan split from the north and declared independence. The fighting near the Sudan-South Sudan border drove tens of thousands of Nuba from their homes.

Nuba fighters sided with the south during Sudan's 21-year civil war. The Khartoum government has ordered armed groups in the border state to move into South Sudan.

Following Sudan's split into two independent nations, South Kordofan is the only oil-producing region controlled by the Khartoum government.