State media in Sudan say nearly 40 people have been killed and dozens wounded in ethnic violence in Um Dafuq, in the state of South Darfur.
It is not clear what sparked the fighting between the Taisha and Fellata groups, but they often clash over access to land and water.
Violence has increased in Darfur since a United Nations-African Union force ended its mission last year.
At least 1.5 million people remain displaced by the conflict which began 18 years ago.
