JUBA, South Sudan — At least 500 people, most of them soldiers, have been killed in South Sudan since Sunday, a senior government official said, as an ethnic rivalry threatened to tear apart the world's newest country.
The clashes apparently are pitting soldiers from the majority Dinka tribe of President Salva Kiir against those from ousted Vice President Riek Machar's Nuer ethnic group, raising concerns the violence could degenerate into a civil war.
Fighting spread on Wednesday to Jonglei, the largest state in South Sudan, where troops loyal to Machar were said to be trying to take control of Bor, the state capital.
Machar himself is the subject of a manhunt by the country's military after he was identified by Kiir as the leader of an alleged coup attempt on Sunday. Machar has denied he was behind any coup attempt.
Barnaba Marial Benjamin, the foreign minister, told The Associated Press late Wednesday that there was heavy fighting in Bor, but he denied renegade soldiers had overtaken it.
"There is fighting there, but (government forces) haven't lost control of the town," he said, accusing Machar of actively mobilizing soldiers to mutiny against the government.
Col. Philip Aguer, the South Sudanese military spokesman, said there was fighting Wednesday among troops in Jonglei state but that it was not clear "who is fighting who."
He said military officials in Juba, the capital of South Sudan, were trying to confirm reports of defections in Bor.