Members of the White Army, a South Sudanese anti-government militia, ride a captured military vehicle in Nasir on April 14, 2014. Conflict in South Sudan has triggered a serious risk of famine that will kill up to 50,000 children within months if immediate action is not taken, the UN has warned. The African country has experienced high levels of malnutrition since it gained independence in 2011, UNICEF said, and conditions have worsened since ethnic conflict broke out between troops loyal to President Salva Kiir and supporters of his former deputy Riek Machar. TOPSHOTS/AFP PHOTO / ZACHARIAS ABUBEKER