KAMPALA, Uganda — A satellite imagery project monitoring parts of Sudan says it has found new evidence of mass graves in the troubled Nuba Mountains region, where the government has recently waged a fierce campaign to stamp out rebels.

In a report scheduled to be published Wednesday, the Satellite Sentinel Project contends that as many as eight mass graves have been dug in the area since June, including two new sites discovered in the past week. It says the images show body bags, vehicles and machinery used to dispose of the dead.

The information and images provided by the project follow multiple allegations by residents and human rights advocates that the Sudanese government and its aligned forces have carried out widespread killings and other abuses against civilians in the region this summer. The Sudanese government rejects the assertion, saying it has taken aim solely at the rebels, not at civilians.

“The pictures do not show the truth,” Rabie A. Atti, a Sudanese government spokesman, said Tuesday. “Behind them I think it is the rebels that falsify such rumors, to bring the international community to intervene in this domestic crisis.”