At least two dozen people, most of them women, have been killed over the past week in ethnic violence between Bantus and Pygmies in southeastern Democratic Republic of Congo, a U.N. human rights official said on Monday. The Luba, a Bantu ethnic group, and the Twa, a Pygmy people who inhabit Central Africa’s Great Lakes region, have been in conflict since May 2013 in Congo’s Katanga region, known for its rich deposits of copper and other metals.