Almost half a million South Sudanese have fled the fighting which began one month ago, and the majority of those still inside the country are not getting any aid, the United Nations said on Tuesday.
An estimated 413,000 people have been displaced inside South Sudan and 74,300 have crossed regional borders as refugees, the U.N. said in its latest update. Between 4,000 and 5,000 are crossing into Uganda daily, it said.
The world's youngest state, home to 11.8 million, is experiencing its worst crisis since independence two years ago. Government and rebel forces are fighting over key towns, and peace talks in neighbouring Ethiopia have stalled.
Aid agencies have helped 203,000 of the internally displaced, just under half the total. Most of these are in rural areas, such as Awerial County. The 65,000 people sheltering in U.N. bases around the country have been getting some aid. About one in 25 of the population have been uprooted from their homes.
"Humanitarian access remained challenged by the ongoing hostilities, with aid flights still unable to go to Bor due to a lack of safety assurances from the conflict parties and irregular access to other areas including Bentiu and Malakal," the U.N. update said.
The government has been fighting to recapture Bor from rebels for several weeks and conditions are difficult for 8,000 people sheltering in the town's U.N. base. Some food stocks have been retrieved from a warehouse in the town and are being distributed to civilians inside the base, the U.N. said.
The government took control of Bentiu from rebels on Friday, its advance on the town causing an exodus of civilians and aid agency staff.
Some agencies have returned to help around 8,500 people sheltering inside the Bentiu U.N. base, Concern Worldwide's country director, Elke Leidel, said in a telephone interview on Tuesday.
"For the moment, for security reasons, we have to work in confined spaces, which means the U.N. base," she said.
"It seems to be quite challenging there; open defecation everywhere because there are not sufficient latrines. It's still quite crowded," she said, citing reports from two sanitation experts working for Concern Worldwide who flew to the U.N. base on Monday.
She said the town was largely burnt during the fighting, agencies' compounds were looted and their vehicles taken by combatants.
"Many organisations are still hesitant to send staff into locations such as Bentiu, where there are currently no active hostilities but where the security situation is unpredictable," the U.N. said.
"While it is difficult to predict how hostilities will evolve, reinforced security analysis, risk mitigation measures and joint security standard procedures for NGOs and UN agencies could assist in making sure aid agencies are present in as many locations as possible."
Fighting was reported in Malakal on Tuesday, as rebels advanced on government positions. Some 20,000 people are sheltering in the town's overcrowded U.N. base.