The United Nations has launched an appeal for nearly $100 million -- It's aimed at helping the hundreds of thousands of people displaced by humanitarian crises in South Sudan and the Central African Republic.<br/> <br />According to the U.N. High Commissioner for Refugees, the funds are for South Sudanese and Central Africans who are internally displaced as well as those fleeing for safety.<br/> <br />Three weeks of fighting, often along ethnic lines, is raising international concern that the conflict could spiral into a full-blown civil war.<br/> <br />The U.N. estimates some 43,000 South Sudanese have fled to neighboring countries, and it fears the number could rise to 125,000.