An army general was reportedly killed in fighting outside a rebel-held town in South Sudan last night as peace talks got under way in neighbouring Ethiopia.
A convoy of Government troops including a commander general - who has not been named - came under fire as it advanced on Bor, according to the BBC.
More than 1,000 people are believed to have been killed during three weeks of clashes between rebels and the Government of the world's newest state.
The fighting began in the capital Juba and has spread along ethnic faultlines.
It has forced a cut in oil output and left the world's newest state on the brink of civil war.
Juba has been largely calm since the early clashes, though there was also a brief gun fight on Saturday evening and residents talk of growing tensions.
"I saw a truck full of soldiers going along the Bilpam road. They were singing. About 20 minutes later the shooting started and people started running towards town," said Animu Afekuru, who lives in the neighbourhood.
Western and regional powers, many of which supported the negotiations that led to South Sudan's secession from Sudan in 2011, have been pressing for a peace deal, fearing the latest fighting could destabilise east Africa.
The unrest pits President Salva Kiir's SPLA government forces against rebels loyal to former vice president Riek Machar.
Both warring factions have said they want peace and are committed to a ceasefire in principle.
But there is widespread scepticism in Juba.
"I fear for our country in the coming days," 19-year-old Nyathok Khat told Reuters. "The politicians don't care about the suffering of the people."
U.S. Secretary of State John Kerry on Sunday voiced his support for the Addis Ababa peace talks and warned against the use of force by either side to gain the upper hand.
A key point issue is what should happen to a number of political detainees allied to Machar who are accused of involvement in the plot.
The rebels have demanded their comrades' release - a call backed by the United States and European Union.
Video: UN: South Sudan faces "humanitarian catastrophe"