Thousands of people in the Baggari area of Wau County fled into the bush and were surviving on wild roots, according to UN Office for the Humanitarian Affairs or OCHA report.
The Office after its assessment team visited Baggari area on May 20, said homes were burnt and clinics were damaged.
The team estimated that about over 21 thousand people were displaced following the fighting in February 2016.
OCHA reported that there were sexual and gender-based violence and killing of civilians including children.
Displaced people are sleeping in the open and lack food, shelter, basic household items, health services and nutritional support, the Office said.
Insecurity remains a concern for the displaced people in and around Wau town, OCHA noted.
The assessment found that fighting continued in Bussere and Moimoi, Bazia areas of the Wau on May 10 and from May 15 to 17 in Menemba A Boma.