Tensions have risen sharply after security forces arrested several senior officials from the opposition group, SPLM-IO. A fragile power-sharing arrangement between President Salva Kiir and First Vice President Riek Machar is threatened by conflicts among their allied troops in Upper Nile State. For more insight, VOA's Paul Ndiho spoke to Reith Tang, a South Sudan's National Legislative Assembly member and Deputy Chairperson of the National Committee on Foreign Relations SPLM -IO.