An independent expert with the United Nations expressed grave concern over what they said appears to be targeted mass killings in South Kordofan in Sudan. South Sudan became the world's newest nation July 9 and later the 193rd member of the United Nations. Independence was part of a peace agreement reached in 2005 that ended a brutal civil war in Sudan. Officials have expressed concern about violence along the border between the two Sudans. Gay McDougall, an independent expert on minority issues for the United Nations, said there were troubling signs that members of the Nuban ethnic community were targeted. If proven, the atrocities committed may constitute war crimes, she said. "We are gravely concerned by what appears to be strong evidence that atrocities are being carried out right now in South Kordofan and credible reports that civilians as well as combatants are being killed and targeted for gross and widespread human rights violations by Sudanese government forces," she said in a statement. Satellite imagery reportedly indicates there are mass graves related to ethnic violence in South Kordofan state along the border, though officials in Khartoum denied civilians were targeted in any attacks. U.N. officials had said there was evidence that at least 150 bodies were discovered in the region that bore the characteristic skin color of Nuban descent. The U.N. Office of the High Commissioner for Human Rights said Sudan army and paramilitary forces were also targeting U.N. peacekeepers in the region.