More than 130 people have been killed in tribal clashes in Sudan's oil-rich region near the border with South Sudan.
The Ziyoud and Awlad Omran clans have been fighting for several days over disputed land in West Kordofan. Both clans are sub-groups of the powerful Arab Mesiria tribe.
Tribal leader Mukhtar Babo Nimir told reporters Thursday that heavy weapons have been used in the fighting. He said there were no government groups in the area yet.
There was no immediate comment from Sudan's government.
Khartoum armed many Arab tribes during Sudan's civil war, which ended with in 2005 and led to the secession of South Sudan.
After the split, South Sudan took control of most oil fields, making West Kordofan the main oil-producing region north of the border.