JOHANNESBURG, South Africa — At least 12 people were killed when an armed mob overran a United Nations peacekeeping camp in Bor, South Sudan, in an attack targeting ethnic Nuer.
South Sudan was torn by ethnic violence when the country's ruling party and army split along ethnic lines in December as a result of a political struggle. Fighting has continued on and off ever since, and peace talks in neighboring Ethiopia have failed to stem the violence.
U.N. officials strongly condemned Thursday's attack by armed men, some wearing military uniforms, on the U.N. base in Bor where about 5,000 Nuer had sought refuge from ethnic violence. Nuer are the second-largest group after the Dinka.
Bor, the capital of Jonglei state, has changed hands several times since fighting broke out in December. In one attack this year most of the city was burned and looted. In another, Nuer militias invaded a hospital, killing those too weak to run away.
South Sudan gained independence in 2011. Despite international aid and support, it has suffered massive challenges, including corruption, theft of government money, ethnic violence and political infighting in the ruling Sudan People's Liberation Movement.
The conflict in the SPLM worsened last year when President Salva Kiir sacked his Cabinet after prominent figures announced they planned to run against him for president next year.
Analysts said the outbreak of fighting in December came at the worst possible time, with the World Bank and International Monetary Fund preparing to pour in finance and the Chinese government planning to invest billions of dollars in infrastructure, such as roads, schools and hospitals. After the fighting broke out, the deals were put on hold.
The assailants got access to the U.N. compound in Bor on Thursday by pretending to be a peaceful group of protesters who wanted to hand in a petition to the world body. Instead, some of them opened fire on civilians in the camp, according to the U.N.
"There is no excuse for direct attacks on civilians or on those risking their own lives to protect them," said Toby Lanzer, the U.N. humanitarian coordinator in South Sudan.
Lanzer said U.N. security forces fired warning shots to disperse the mob but they had no effect.
It was not immediately clear who was killed and by whom.
"These events show, yet again, the pointlessness of the violence engulfing South Sudan. The current cycle of revenge will get the people of this country nowhere. It wrecks the present, and casts a dark shadow over what should have been a very bright future," he said.
Lanzer called on both parties to return to negotiations.
"The secretary-general reminds all parties that any attack on United Nations peacekeepers is unacceptable and constitutes a war crime," the statement said.
A U.N. statement Thursday said the South Sudan government bore primary responsibility for the protecting members of its population and maintaining public order.
The latest attacks come after renewed fighting in Bentiu, in South Sudan's oil-rich north. Rebels associated with former Vice President Riek Machar announced Wednesday that they had retaken the town, which has changed hands multiple times because of its strategic importance.