Thousands of angry demonstrators in the South Darfur state capital Nyala clashed with police on Thursday as they protested the murder of a businessman a day earlier, witnesses said.
Police fired live ammunition and teargas when the protesters set ablaze government buildings and attacked the governor's car, a witness told AFP, saying that at least four people were wounded.
Other witnesses said several thousands demonstrators marched on the city centre, chanting, "The people want the downfall of the regime" and "Get out, get out."
They condemned the murder of a businessman on Wednesday in Nyala, but details about the killing were unavailable.
Non-Arabs in Darfur rose up 10 years ago against what they saw as the domination of Sudan's power and wealth by Arab elites.
In response, government-backed Janjaweed militias shocked the world with atrocities against them.
The devastating conflict has killed at least 300,000 people and left 1.8 million displaced in Darfur, according to United Nations. Khartoum talks about 10,000 deaths.
But though violence has declined, the region remains volatile due to tribal conflicts, kidnappings and other crimes, many of which are linked to government-backed militias and paramilitary groups.