Tens of thousands of people who have fled tribal violence in a remote area of South Sudan are in desperate need of food, the United Nations said on Saturday.
South Sudan became Africa's newest nation in July after a referendum agreed under a 2005 peace deal with Khartoum that ended decades of civil war.
But the government in Juba has been struggling to assert its authority over a country roughly the size of France and end tribal and rebel violence that killed thousands last year.
Fighting broke out last week between the Lou Nuer tribe and the rival Murle tribe in a remote area of the state of Jonglei. Some 6,000 armed Lou Nuer members attacked the main Murle town of Pibor on Monday.
Around 60,000 people were hiding in the bush and many had lost their settlements or grain storages, Hilde Johnson, U.N. Special Representative for South Sudan, said.
"There is a desperate need for food, for shelter and assistance," Johnson said after visiting the affected area and meeting displaced people.
"(Some) haven't had food for two to three days ... They drink water from the river," she said.
There was little damage to huts in Pibor but about a third of settlements in the affected area had been torched, Johnson said, adding that fighting between the Lou Nuer and Murle seemed over for now.
Ravaged by civil war, South Sudan is one of the least developed nations. Legislation since independence is still in the early stages. Few roads exist outside the capital Juba, while the economy entirely depends on oil.