Major aid agencies have evacuated Bentiu, the capital of South Sudan's oil-rich Unity state, joining thousands of residents who have fled the town fearing a government offensive to recapture it from rebels is imminent.
Bentiu is one of two northern towns captured by rebels loyal to former vice president Riek Machar soon after violence erupted in South Sudan on Dec. 15.
Clashes have spread across the country in the worst violence since independence in 2011, pushing South Sudan to the brink of civil war. Over 1,000 people have been killed and 230,000 displaced.
Civilian residents poured out of Bentiu on Wednesday night, the medical charity Medecins Sans Frontieres (MSF) told Thomson Reuters Foundation. Both the MSF and the ICRC have evacuated the town.
"Today, in Bentiu town, there are no more civilians, according to our information, except in the UNMISS camp," Raphael Gorgeu, MSF's head of mission in South Sudan, said in a telephone interview on Thursday.
Some 8,000 civilians have been sheltering in the U.N.'s military base in Bentiu since the town was captured by rebels.
"We've placed extra teams (women & men) at the #UNMISS gates to ensure that all civilians trying to enter can do so safely," United Nations humanitarian coordinator Toby Lanzer, who is in Bentiu, tweeted on Wednesday night.
"Thousands of civilians on the move out of town, carrying everything they can... Use of heavy armaments around town is audible."
ESCALATION OF VIOLENCE
The MSF has evacuated its staff from Bentiu hospital and the U.N. base where they had been treating wounded civilians and displaced children with diarrhoea and respiratory infections.
"We were getting information that Bentiu might be attacked very soon. So we decided to relocate our team in a place called Leer, which is basically 3-1/2 hours by car from Bentiu, where we have a full hospital with surgical capacity," Gorgeu said.
The International Committee of the Red Cross has also pulled out.
"Due to the escalation and volatility of the violence, the ICRC has had to temporarily move its team to a safer location further away from the hostilities," Jacob Kurtzer, the ICRC's South Sudan spokesman, said in an email.
"It continues to work on monitoring the situation and is on standing ready to return as soon as security conditions permit with a view to respond to the considerable humanitarian needs."
UNABLE TO KEEP WALKING
An MSF medical team is on the road 20km south of Bentiu, helping fleeing civilians.
"We see that a lot of people are leaving Bentiu on foot or with cars," said Gorgeu. "We sent a team from Leer to the road from Leer to Bentiu today to see how many people we are talking about, what would be the needs, where are they going, to see how we can provide assistance."
The MSF team will see where they can put up water points and basic health clinics to support people on the move, and those who are very ill and unable to keep walking will be taken to hospital in Leer, Gorgeu said. The health of women and children walking long distances with luggage can deteriorate quickly, he said.
There is limited humanitarian access to many towns in northern South Sudan because of the fighting. Aid agencies have called for a ceasefire to allow food, medicine and plastic sheeting and other emergency aid to be delivered to the displaced.