ADDIS ABABA - Peace talks between South Sudan's government and rebels aimed at ending a four-month-old civil war resumed in the Ethiopian capital on Monday, amid mounting global outrage over a wave of atrocities.
The long-awaited resumption of the talks, which have been on hold for several weeks against a backdrop of heavy fighting, came as top UN human rights officials arrived in the country to probe massacres and other war crimes.
"The South Sudan peace talks that focus on a political dialogue for national reconciliation and healing resumed in Addis Ababa today following the arrival of all parties," a statement from the IGAD regional bloc said.
It added that both sides "shared concern over the recent escalation of the conflict and expressed their renewed commitment to the mediation process."
The stop-start talks began shortly after the conflict broke out on December 15 between supporters of President Salva Kiir and ex-vice president Riek Machar. A ceasefire was signed in late January but was quickly violated.
With the UN Security Council last week threatening sanctions against leaders on both sides, it is hoped the new round of talks will have more success in ending the conflict in the world's youngest nation, which won independence from Khartoum in 2011 but has collapsed into all-out war and, according to aid workers, is on the brink of famine.
The war has left thousands and possibly tens of thousands of people dead, and forced over one million to flee their homes. More than 78,000 civilians are currently crammed into eight UN bases in the country, while thousands have fled to neighbouring states, mainly Uganda and Ethiopia.
The capital Juba was also hosting a visit by the UN's High Commissioner for Human Rights, Navi Pillay, and special envoy for the prevention of genocide, Adama Dieng.
The two are expected to remain in the country until Wednesday and hold meetings with Kiir. They are due to tour massacre sites "if security conditions allow", UN Mission in South Sudan spokesman Joe Contreras said.
Earlier this month, the rebels were blamed for the killings of hundreds of people in the oil hub of Bentiu, and a pro-government mob killed dozens of civilians in an attack on a UN base in Bor.
More details on the Bentiu atrocities emerged on Monday, with the international aid agency Doctors Without Borders (known by its French acronym MSF) releasing fresh eyewitness testimony of the carnage.
"What I saw in Bentiu -- bodies of civilians strewn through the streets in grisly states of damage and decay, being eaten by dogs and birds -- was an affront to humanity," said Raphael Gorgeu, MSF's head of mission in the country.
"The violence in South Sudan has taken a particularly ugly turn, stripping people of their most basic human dignity. It is a terrible thing to witness."
Christopher Lockyear, MSF's operations manager for South Sudan, said staff had "heard tales of horrific brutality taking place on the hospital grounds" in Bentiu, and had credible information of up to 33 people killed in Bentiu State Hospital when the town fell to rebels.
"People who fled to the hospital in search of safety were selectively targeted based on their identities and loyalties. Once again in South Sudan, we see hospitals -- places that should be protected safe havens -- are increasingly places of attack and cruelty," he said.
Last week the UN Security Council raised the threat of sanctions against both sides in the conflict who have been implicated in atrocities and war crimes including massacres, rapes, attacks on UN bases sheltering civilians from ethnic violence and the recruitment of child soldiers.