The U.N.-African Union assistance mission in Darfur said an investigative team was turned away from a checkpoint by Sudanese authorities after reports of an attack in Darfur. UNAMID said it received reports that 13 people died in the latest violence.
Human Rights Watch said residents attributed the violence to an ethnic militia operating in the area though it wasn't able to confirm the reports on the ground. The militia is seen as loyal to the Sudanese military.
The rights group said Sudanese authorities have a history of blocking peacekeepers from investigating reports of violence in Darfur.
"Sudan's repeated refusal to let international peacekeepers do their jobs should not go unchallenged by concerned governments," said Daniel Bekele, Africa director at Human Rights Watch, in a statement from neighboring Kenya. "The U.N. Security Council should demand answers from the Sudanese government."
A South African member of UNAMID was killed when gunmen ambushed a patrol near Darfur in late October.