Sudan called on Thursday for an investigation into the "assassination" of its nationals in a South Sudan oil town, where the UN has accused rebels of killing hundreds of civilians. "The foreign ministry condemns assassination of the Sudanese nationals in Bentiu and calls for urgent investigation", the official SUNA news agency said in an SMS alert. The United Nations Mission in South Sudan (UNMISS) said on Monday that both South Sudanese and Sudanese -- some from Sudan's Darfur region -- were killed in "targeted killings" after rebels took Bentiu, the capital of South Sudan's oil-rich Unity state, from government forces last week. Civilians including children were also massacred at a church, hospital and an abandoned UN World Food Programme compound, it said.