President Salva Kiir and his former deputy Dr Riek Machar may be investigated by the United Nations over crimes against humanity.

The UN Security Council had demanded an immediate end to all human rights violations and abuses and stressed that those responsible would be held accountable. 

On Tuesday, the UN Assistant Secretary-General for Human Rights, Ivan Šimonovic, visited Juba to assess the extent of human rights abuses in the war pitting former government soldiers supporting President Salva Kiir and his former deputy, Dr Riek Machar.

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UN figures show that nearly 500,000 people have been displaced while nearly 7,500 people have fled to Uganda, Sudan, Kenya and Ethiopia.

Mr Simonovic, who noted that there have been cases where people are tied to trees before being shot, has posted 92 UN investigators to South Sudan who are expected to come up with a report in two weeks.

The UN mission to South Sudan (UNMISS) investigations in Bentiu and Malakal have revealed “horrific atrocities by anti-government forces against civilians and surrendering soldiers, including summary executions, torture, sexual violence and ethnically targeted killing,” UNMISS said in a press statement.

The Machar group has been accused of committing human rights violations in Upper Nile and Unity States.

A report prepared by the Kenyan ministry of foreign affairs has also indicated that those supporting President Kiir had massacred close to 300 people in Juba immediately after the outbreak of violence in mid-December.

The UN is concerned about the safety of those who have been arrested or detained by government agents who have been carrying out house-to-house searches. Human rights groups have now started campaigns for the International Criminal Court to start investigating war crimes in South Sudan.

However, such a process can only begin if the United Nations Security Council refers the South Sudan situation to the ICC by adopting a resolution under Chapter VII of the UN Charter as happened in the case of Libya and Darfur.

In the meantime, mediation talks between the two groups in Addis Ababa under the Inter-Governmental Authority on Development (Igad), have stalled after President Kiir recalled his mediation team to Juba for further consultations.

Juba has also summoned all its foreign envoys for a de-briefing on foreign policy, in a move analysts say was meant to gauge which countries are supportive of the government and which ones are sympathetic to Dr Machar.

Negotiators for Dr Machar are now demanding the withdrawal of Ugandan troops as a key condition for signing a ceasefire to end fighting in Africa’s youngest nation.