Some 20,000 residents of the town of Katela were forced to flee after fighters with the Bani Halba tribe attacked the town, burning it to the ground, the Sudan Tribune reported Thursday.
Two policemen defending police headquarters were reported killed. Two Bani Halba fighters died and nine others were injured.
Abakar al-Tom, a spokesman for the al-Gimir tribe, accused the state government of South Darfur of colluding with the attackers. He said government troops withdrew from the town shortly before about 1,000 Bani Halba fighters attacked.
State officials declined to comment on the accusations.
Al-Gimir tribal officials said they have sent a delegation to the African Union-United Nations Mission in Darfur to file a complaint.
In January, seven people died and four were injured in fighting between the two tribes.