South Sudanese officials say government troops are fighting rebels in the flashpoint town of Bor. The rebel fighters are believed to be loyal to former Vice President Riek Machar.
Officials said fighting broke out in the city of Bor, 190 km (120 miles) to the north of the capital, Juba, late on Monday.
“We are fighting the rebels now,” the mayor of Bor, Nhial Majak Nhial, told Reuters news agency by phone on Sunday, with bursts of gunfire audible in the background.
Bor, the capital of the eastern state of Jonglei, has been the site of a power struggle over the past two weeks, having been captured by rebels before being retaken by government troops a week ago.
It was not clear if the rebels attacking the city are the “White Army” militia that has been advancing on the city over the past few days. The “White Army” is composed of ethnic Nuer fighters loyal former Vice President Riek Machar, who has come out in opposition to President Salva Kiir of the ethnic Dinka group.
The rivalry between the two men has fanned ethnic differences in the country, with open violence erupting on December 15 when Kiir blamed his former deputy for mounting a coup.
Thousands are feared dead, with fierce fighting reported from strategic oil-producing areas.