Soldiers loyal to President Salva Kiir seek to wrest control of the city, the capital of central Jonglei State, from rebels aligned with his political opponent and former deputy, Riek Machar.
Despite international efforts to bring the two men to the negotiating table, Kiir told parliament on Monday that the army is “ready to move” on Bor, which fell under rebel control following the defection of a powerful local general.
Army spokesman Colonel Philip Aguer said the battle for Bor, which sits just 125 miles north of the capital Juba, is imminent. “The army has a responsibility to restore peace and stability in the region. The move to take Bor can happen anytime from yesterday,” he told GlobalPost on Monday.
The descent into turmoil and the possible resumption of civil war in the world’s newest nation worries regional governments who fear the instability will spread across borders.
It also concerns foreign powers. The US in particular is heavily invested in South Sudan’s stability after playing a key role in ending the last civil war, which raged for 22 years and killed an estimated 2 million people.
The current conflict was triggered by rumors of the arrest of Machar on Dec. 15, which led to fighting within a military unit in the capital, Juba.
Kiir, a member of the majority Dinka tribe, accuses Machar, a Nuer, of an attempted coup. Machar denies the allegation but has fled Juba and is coordinating a spreading rebellion from an unknown location.
The long-standing political rivalry between the two men has burst violently into the open and become increasingly tribal, with both Nuer and Dinka accused of ethnic killings and reprisals.
Another general has now defected in the oil-producing state of Unity, taking control of the main town, Bentiu, and aligning himself with Machar.
Army spokesman Aguer said that after Bor, the army will advance on rebel-held Bentiu. “Bentiu is highly vital and important and we must retake it,” he said.
Fighting has now been reported in six of South Sudan’s 10 states. On Monday, the medical aid agency Medecins Sans Frontieres, or Doctors Without Borders (MSF), said it treated 24 patients with gunshot wounds after fighting broke out for the first time in Upper Nile State.
“We are deeply concerned for the safety of those caught up in the violence,” said Mike White, MSF’s head of mission in South Sudan.
At least 62,000 people have already been forced from their homes in the latest violence, 42,000 of whom have sought shelter at United Nations compounds, turning the bases into de facto refugee camps.
The UN says that at least 500 people have been killed, but the figure is expected to rise dramatically as information on casualties trickles in from far-flung parts of this vast and underdeveloped country.
Toby Lanzer, the UN’s humanitarian coordinator for South Sudan, visited Bor over the weekend. “There was a lot of looting, a lot of gun shots and a lot of dead bodies," he told the BBC.
Lanzer said people “were being lined up and executed in a summary fashion. This is done by people who are simply out of control," he added.
Despite the intervention of international mediators, including US Special Envoy Donald Booth, who arrived in Juba on Monday, attempts to kickstart negotiations between Kiir and Machar have so far failed — and the fighting is set to intensify.
“There is no easy fight and no tough fight: war is war and we are prepared for anything,” said the army's Aguer.