The SPLM-IO is predominantly Nuer and its head , Machar , had previously committed the Bor massacre of mostly Dinka civilians in 1991 . In 2014 , the Bentiu massacre occurred when Bentiu was recaptured by rebels April 2014 and 200 people were killed in a mosque . Rebels separated the people and picked out those from opposing ethnic groups who they then executed
Bentiu massacre
2014 Bentiu massacre
South Sudanese Civil War