Riek Machar, South Sudan rebel leader, Saturday demanded “proper negotiations” before accepting the government’s offer of a truce. The offer came from President Salva Kiir after fighting between his Dinka and Machar’s Nuer tribes claimed 1,000 lives since the president accused Machar of a coup attempt two weeks ago. Macher told the BBC he had a negotiating team ready but any ceasefire had to be “serious, credible and properly monitored.”  Fighting continued on Friday in the oil town of Malakal, Upper Nile State, as the first UN reinforcements arrived to help some 63,000 seeking help and shelter at  UN compounds.