The United Nations and international aid agencies have begun pulling staff out of Maban County in Upper Nile State where a local militia is accused of the killing at least six aid workers this week.
Acting U.N. Mission in South Sudan (UNMISS) spokesman Joseph Contreras said 220 workers were evacuated from the county on Wednesday.
“The decision reflects deepening concern about the security situation in Maban County," he said. A militia group that calls itself the Mabanese Defense Force has been accused of killing several aid workers in or near the town of Bunj in Maban County, apparently targeting them because of their ethnicity.
The killings appear to be in revenge for losses the militia suffered in late July clashes with Nuer soldiers who defected from the Sudan People's Liberation Army (SPLA).
Killings 'may be war crimes'
U.N. Secretary-General Ban Ki-moon, U.S. Secretary of State John Kerry and the president of the U.N. Security Council, Mark Lyall Grant, have condemned the killings. Lyall Grant said the attacks on civilians and humanitarian personnel "may constitute war crimes."
Most of the agencies withdrawing from Maban have been providing food and shelter to more than 270,000 refugees who fled fighting in South Kordofan and Blue Nile states in Sudan, Contreras said.
He says the aid agencies also run feeding and nutritional programs and provide non-food items including blankets to the refugees.
Contreras said UNMISS sent 120 peacekeepers to protect the local airstrip to facilitate the evacuation of aid workers and the SPLA has sent reinforcements from barracks in the town of Melut to "restore order."