A US-based human rights group has said it has new evidence of mass graves filled with civilian bodies in the South Kordofan region of Sudan, just north of the border with South Sudan.
The United Nations has also called for an investigation into allegations that the Sudanese government has committed war crimes in the area.
The Sudanese government, however, has defended its military operations in the region.
Al Jazeera correspondent 's Kristen Saloomey reports.
Source: Al Jazeera