GENEVA (AFP) - Allegations of summary executions, aerial bombardments of civilians and enforced disappearances in Sudan's South Kordofan region could constitute crimes against humanity or war crimes, the United Nations said on Monday. "If substantiated (the allegations) could amount to crimes against humanity, or war crimes for which individual criminal responsibility may be sought," according to the preliminary results of a UN investigation into a series of incidents in South Kordofan between June 5 and 30. A report prepared jointly by the UN High Commissioner for Human Rights and the world body's mission in Sudan.