JUBA : Regional nations heaped pressure on South Sudan’s warring parties Tuesday to reach a ceasefire to end weeks of bitter fighting and atrocities on both sides that have devastated the young nation.

Meanwhile, South Sudan’s President Salva Kiir has lashed out at the United Nations following heavy criticism including accusations of atrocities in the conflict gripping the young nation.

Kiir’s comments come after UN chief Ban Ki-moon expressed alarm at reports that senior government figures and troops threatened UN staff when they tried to enter a peacekeepers’ compound to which thousands of civilians had fled.  “We did not know that when the UNMISS was brought to South Sudan they were brought as a parallel government... but they have showed it very clearly in this conflict,” Kiir said in a speech on Monday, referring to the UN Mission in South Sudan.

Thousands have been killed and half a million civilians have been forced to flee the fighting between troops loyal to President Salva Kiir and rebels allied to his sacked deputy Riek Machar.

Deadlocked ceasefire talks in Ethiopia are being mediated by the East African regional bloc IGAD, aimed to broker an end to a conflict where the United Nations reports atrocities including mass killings, sexual violence and widespread destruction.

Fighting has spiralled into ethnic killings between members of Kiir’s Dinka people - the country’s largest group - and Machar’s Nuer. Many fear conflict on the ground has spiralled out of the control of the politicians who sparked it.

Leaders of IGAD, the Intergovernmental Authority on Development, are due to hold a one-day summit in Juba on Thursday, South Sudan’s foreign ministry spokesman Mayen Makol said.

“Hopefully it is going to be attended by seven heads of state of IGAD... the key agenda of course is the negotiations in Addis Ababa,” Makol told AFP.

The summit follows a visit Monday by African Union Commission chief Nkozasana Dlamini-Zuma, who demanded both sides end the “senseless killings... and end the humanitarian tragedy unfolding in their country.”

A draft IGAD ceasefire accord, seen by AFP and presented to peace delegates meeting in Addis Ababa, notes the “scale of human suffering... with great loss of human life, destruction of property and massive displacement” since fighting broke out on December 15.

The proposal demands an end to “all military actions”, but also specifically highlights that both sides must “refrain from attacks on the civilian population”, including summary executions, use of child soldiers as well as “rape, sexual abuse and torture”.

Both sides would have to “freeze their forces” in their positions and create aid corridors, as agencies warn of a mounting humanitarian crisis in an already deeply impoverished nation.

Pardon or prosecution?

A separate draft deal urges Kiir to pardon and release 11 key political detainees, one of the key sticking points.

Kiir, in a presidential address on Monday after government forces wrested back full control of Malakal, the last major settlement under rebel control, said that “presidential pardons and general amnesties shall be part of peace efforts”.

Malakal’s recapture, one of the main battlefields since fighting erupted and the key town in oil-producing Upper Nile, came just two days after government troops celebrated the retaking of Bor, capital of Jonglei state.

In Bor, civilians recounted grim stories of how the rebels gang-raped and murdered sick patients in the town’s hospital.

The recapture of Malakal opened up the possibility of a shift in ceasefire talks deadlocked for two weeks, with some suggesting the government had been reluctant to strike a deal while rebels still held urban centres.

Kiir on Monday made a direct appeal to his enemy Machar, while still warning those guilty of crimes would be held “accountable for the atrocities they have committed.”

“I still call Riek Machar and his group to lay down their weapons and come back and participate in the building of our new nation,” Kiir said.

“Nobody will disown them for what they have done. We have a space in our hearts to forgive him and his people.”

Rebels are reported to remain powerful and in control of large areas of the countryside, and battles continue. IGAD includes Uganda as a key member, whose forces have a taken a key role in the fighting in support of Kiir.

Machar has demanded Kampala withdraw all forces, claiming Ugandan fighter jets have tried to kill him.

In Addis Ababa, little progress was seen Tuesday. “The government was having consultations on the issue of withdrawal of Ugandans,” rebel delegate Hussein Mar Nyuot said. “We’ll hear from IGAD and them on all of this later.”