Rebels in South Sudan are forcibly recruiting civilians to march on the capital, the military said, even as representatives of the warring factions gathered in neighbouring Ethiopia today for the start of peace talks.
The fighting underscored the challenge facing African mediators as they try to nudge two rivals - President Salva Kiir and ousted Vice President Riek Machar - towards the negotiating table after more than two weeks of bloody violence in the world's newest country.
South Sudan has been plagued by ethnic tension and a power struggle within the ruling party that escalated after Mr Kiir dismissed Mr Machar as his vice president in July, with the violence boiling over in mid-December. The rebels back Mr Machar, who is now a fugitive sought by the military.
Rebels currently hold Bor, the capital of the key oil-producing state of Jonglei that is seeing some of the fiercest fighting of the conflict. Military spokesman Colonel Philip Aguer said the central government had sent in reinforcements from Juba, the capital.
He said rebels were arming reluctant civilians as they focus on their next target: Juba.
"Juba, that is their intention," he said. "They are trying to march to Juba. The (South Sudanese military) will return them to where they came from."
It was not possible to independently verify Col Aguer's account.
The fighting has overshadowed efforts in neighbouring Ethiopia, which is playing a leading role in trying to extract a cease-fire deal from both sides.
In Addis Ababa, the Ethiopian capital, African mediators under the banner of a regional bloc met representatives for both sides, briefing them separately ahead of the official start of direct talks. Face-to-face meetings between the two groups were not expected to start until later in the week. One delegate from Mr Machar's side said he believed the first direct meetings would happen on Saturday.
Mr Kiir on Wednesday declared a state of emergency in the states of Jonglei and Unity, where rebels also control the capital.
The fighting has exposed ethnic rivalry between the country's two largest ethnic groups, the Dinka of Kiir and the Nuer of Machar. The UN says there is mounting evidence that people were targeted for their ethnicity.
More than 1,000 people have been killed and nearly 200,000 displaced by violence.
Mr Kiir insists the fighting was sparked by a coup attempt mounted by soldiers loyal to Mr Machar on December 15 in Juba.
But that account has been disputed by some officials of the ruling party, who say the violence began when presidential guards tried to disarm their Nuer colleagues. From there, violence spread across the country, with forces loyal to Mr Machar defecting and seizing territory from loyalist forces.
South Sudan's government said in Twitter updates that the military had formed committees to "investigate those involved in killing people," as well as the fight among presidential guards. It also said "criminals" accused of looting from civilians had been arrested.
Mr Machar has criticised Mr Kiir as a dictator and says he will contest the 2015 presidential election.
South Sudan peacefully broke away from Sudan in 2011 following a 2005 peace deal. Before that, the south fought decades of war with Sudan.
In New York, UN humanitarian chief Valerie Amos today said that some 194,000 South Sudanese have been driven from their homes by the violence, and more than 57,000 are under protection at UN peacekeeping bases.
She said the United Nations has provided 107,000 with UN assistance, and the world body aims to reach over 600,000 South Sudanese with humanitarian aid in the next three months.