Fighting in South Sudan has killed up to 500 people, according to the United Nations, which fears the violence in the oil-rich East African country is "largely along ethnic lines." The US has ordered its citizens to leave the country immediately. The president of South Sudan—the world's newest country—has blamed the violence on a failed coup attempt by soldiers loyal to his former deputy, who belongs to a different ethnic group.
As tens of thousands of people seek refuge at UN compounds in the capital, there are "disturbing reports of ethnically-targeted killings," with most of the fighting pitting soldiers from President Salva Kiir's majority Dinka tribe against those from former deputy Riek Machar's Nuer tribe, says the South Sudan analyst for the International Crisis Group. The government says 10 people have been arrested in connection with the alleged coup plot, and five remain at large, including Machar, whom the US Embassy says it is not harboring. (Read more South Sudan stories.)