The United Nations human rights chief has expressed concern over the condition of human rights in strife-torn South Sudan and urged both sides to respect cessation.

“We from the outside think the situation is very grave and there might be revenge killings. You know when there is a dispute between two leaders, as we say in Africa when two elephants fight it's the grass that suffers,” Navi Pillay said during her visit to South Sudan.

“I hope that the cessation of hostilities agreement will be respected by both parties – that is the immediate concern. People do not feel safe,” Pillay underlined.

The political crisis in South Sudan began after President Salva Kiir, an ethnic Dinka, accused rebel leader Riek Machar, a Nuer, of attempting a coup in December 2013.

The conflict soon turned into an all-out war between the army and defectors, with the violence taking on an ethnic dimension that pitted the president’s tribe against Machar's.

Thousands of people have so far been killed and more than one million displaced in the war. Over 78,000 civilians are presently forced to live in eight UN bases in the country, while many others have fled to neighboring states, particularly Uganda and Ethiopia.

South Sudan gained independence in July 2011 after its people overwhelmingly voted in a referendum for a split from the North.

The government in Juba is grappling with rampant corruption, unrest and conflict in the deeply impoverished but oil-rich nation left devastated by decades of war.