The United Nations has discovered an additional 38 potential mass graves in Congo's central Kasai region, the director of the UN Joint Human Rights Office in Congo said on Wednesday. The discovery brings the total of mass graves, announced by the UN or the Congolese authorities, to about 90 in the region. The 38 new graves include 31 in Diboko and seven in Sumbula in Kasai's western Kamonia territory, dpa quoted Jose Maria Aranaz as saying in the capital, Kinshasa. They were discovered by a joint investigation by the UN and the Congolese military judiciary between July 4 and 7, he added.