South Sudan rebel leader Riek Machar has told the BBC that treason charges laid against him and some of his allies are quot;baselessquot;. Mr Machar, who is on the run, said he hoped mediators in the crisis would ensure the release of four of his imprisoned allies. Analysts say the issue threatens a ceasefire signed last week. Officials announced earlier that seven politicians were being charged over an alleged coup attempt in December. It was initially a political dispute between President Salva Kiir and his former deputy Mr Machar on 15 December. Since then, violence has spread into a full-scale conflict, with reports of ethnic killing. Continue reading the main story Analysis James...