Thirty-nine civilians were killed, most of them women and children, when shelling hit their homes on Tuesday in Sudan's vast western region of Darfur, medics and witnesses have said.
According to sources, the attack took place in Nyala, the capital of Darfur South state, where 50,000 people have been forced to flee since August 11, the UN has said.
The war between Sudan's army, led by Gen Abdel Fattah Al Burhan, and the Rapid Support Forces, under the control of Gen Mohamed Dagalo, has raged on since April 15.
The conflict, which started in the capital Khartoum, has spread to the western region of Darfur, Kordofan and Jazira state, killing thousands and forcing millions to flee their homes.