File photo taken on Dec. 7, 2013 shows the Central African Prime Minister Nicolas Tiangaye leaving the Elysee presidential palace after a summit on peace and security in Africa held in Paris, France. Interim prime minister of Central African Republic Nicolas Tiangaye has resigned, the Economic Community of Central African States (ECCAS) said in a statement on Jan. 10, 2014. (Xinhua/Etienne Laurent)