JUBA/UNITED NATIONS (Reuters) - The U.N. Security Council approved plans on Tuesday to almost double the number of peacekeepers in South Sudan in a bid to protect civilians from violence as reports of mass graves fueled fears of ethnic bloodshed in the world's newest state.
The 15-member council unanimously authorized a plan by U.N. Secretary-General Ban Ki-moon's to boost the strength of the force in South Sudan to 12,500 troops and 1,323 police, as some 45,000 civilians seek protection at U.N. bases.
The additional U.N. troops and police will reinforce U.N. bases where civilians are seeking shelter. But Ban warned, "Even with additional capabilities, we will not be able to protect every civilian in need in South Sudan."
Violence erupted in the capital Juba on December 15 and quickly spread, dividing the land-locked country of 10.8 million along ethnic lines of Nuer and Dinka. South Sudan seceded from Sudan in 2011 under a peace agreement to end decades of war.
"My cousin and nephew were both caught and executed. How can I leave this place?" asked Gatjang, a 29-year-old Nuer at a U.N. base in Juba where thousands of civilians were crammed. "Even here. What if they sneak inside and attack us?"
Western powers and east African states, keen to prevent more chaos in a fragile region, have tried to mediate between President Salva Kiir, a Dinka, and rebel leader Riek Machar, a Nuer, who was vice president until Kiir sacked him in July.
"Whatever the differences, nothing can justify the violence that has engulfed their young nation," Ban told the council after the vote. "There is no military solution to this conflict. This is a political crisis which requires a peaceful, political solution."
OIL OUTPUT REDUCED
The fighting is affecting oil production, which accounts for 98 percent of government revenue. Petroleum Minister Stephen Dhieu Dau said output had fallen by 45,000 barrels per day to 200,000 bpd after Unity state oilfields shut down.
Dau said production in Upper Nile state, where most of South Sudan's oil is extracted, was safe and outside the reach of rebels.
Kiir said on Tuesday that government troops had retaken control of the Jonglei state capital Bor, a key town that last week fell to rebels loyal to Machar.
Ban said three U.N. personnel were injured at a U.N. base in Bor on Tuesday.
Most fighting has involved Dinka and Nuer factions of the Sudan People's Liberation Army, with militias and marauding youths also reported to be attacking rival ethnic groups. Kiir and Machar both have said the conflict is political, not tribal.
U.N. High Commissioner for Human Rights Navi Pillay said a mass grave believed to contain the bodies of 75 ethnic Dinka soldiers had been discovered in the rebel-held city of Bentiu, capital of Unity state.
The U.N. mission in South Sudan, known as UNMISS, said in a statement later on Tuesday that it could not confirm the report of a mass grave. It said reports now suggested that "this is an inflation of a skirmish resulting in about 15 fatalities, with details to be confirmed."
The Juba government said it was not responsible for a mass grave in Bentiu, and messaged on Twitter: "Bentiu is currently under the control of the rebel leader Riek Machar - we have nothing to do with that area & the mass killings #SouthSudan."
Pillay said in a statement that there were also "reportedly at least two other mass graves in Juba." UNMISS said it was investigating reports of atrocities.
She urged both sides to protect civilians, and said political and military leaders could be held to account for crimes. "Mass extrajudicial killings, the targeting of individuals on the basis of their ethnicity and arbitrary detentions have been documented in recent days," she said.
AFRICAN UNION, U.S. URGE TALKS
Hilde Johnson, the U.N. Special Representative of the Secretary-General, said a previous estimate of 500 dead, made on the third day of the 10-day-old conflict, would rise.
"It is likely that the numbers are much higher than initial calculations but we do not know," she told reporters in Juba.
The U.N. Office for the Coordination of Humanitarian Affairs said the crisis had displaced an estimated 81,000 people, though the real number was likely to be higher.
U.N. envoys on prevention of genocide and responsibility to protect, Adama Dieng and Jennifer Welsh, warned in a statement, "Targeted attacks against civilians and U.N. personnel, such as those that occurred in Juba and Jonglei, could constitute war crimes or crimes against humanity."
While Kiir and Machar have said they are open to talks, Machar said on Monday he would only negotiate if his detained political allies were released, a demand the government swiftly rejected.
The African Union's Peace and Security Council on Tuesday called on Kiir to "consider releasing the political personalities currently detained in Juba, in order to facilitate dialogue and to encourage them to contribute positively to the search for a solution."
U.S. State Department spokeswoman Jen Psaki said in a statement that U.S. Secretary of State John Kerry had urged Kiir and Machar on Tuesday to accept a cessation of hostilities and begin mediated political talks.
She said Donald Booth, the U.S. special envoy to South Sudan, was in Juba trying to secure a final commitment from Kiir and Machar to begin talks.