Angry mobs Monday attacked a UN compound in South Sudan's Upper Nile State, alleging discrimination against the locals in employment.
The unruly mobs damaged vehicles, ransacked offices and set some buildings ablaze at the Maban camp.
They complained that most of the aid workers at Maban were from Equatoria, in the south of the country.
An aid worker, who requested to remain anonymous as she is not authorised to speak to the media, said tensions had remained high between the local youths and the aid agencies in the area for a about a week.
A liaison officer for an international NGO in South Sudan, who also requested anonymity, said the situation had been tense since last week.
"Yeah, the tension was palpable since last week, but we were unaware that it would result to this," he said on the telephone..
Efforts to get a comment from the United Nations Mission in South Sudan (UNMISS) were unsuccessful as multiple telephone calls to their offices were not answered.
The Upper Nile base that borders the Blue Nile State in Sudan, hosts an estimated 170,000 refugees and returnees from Sudan.