As clashes between rebels and government troops intensify in unity state of South Sudan, aid agencies withdraw while 100.000 new migrants are forced to leave their homes.
"Since the beginning of May, military activities south of Bentiu in Unity State have forced up to 100,000 people from their homes," Toby Lanzer, the UN's humanitarian coordinator for South Sudan told AP.
"People should never be harmed, and certainly not targeted or forced to flee from their homes," he added.
Fearing clashes, two global aid agencies, Doctors without Borders (MSF) and the International Committee of the Red Cross (ICRC) evacuated their staff from Sudan.
"Today, we withdraw again with a heavy heart, because we know how civilians will suffer when they are cut off from critical, lifesaving medical care," Paul Critchley, head of mission at MSF said.
“Government checkpoints and bad roads have prevented aid workers and UN staff including human rights monitors from reaching areas affected by the fighting,” said UN Spokesman Joe Contreras.
The President of South Sudan, Mr Kiir and former Vice President of South Sudan Mr Machar signed a ceasefire deal in January this year, but violence has continued in parts of the country.
The UN estimated 10,000 people have been killed and another 1.5 million displaced since the conflict began.
Kiir's term as president ends in July, four years after South Sudan gained independence to become the world's newest country.