Amnesty International has urged the African Union and the international community to quickly establish a mechanism to investigate, collect and preserve evidence of war crimes committed in the conflict.

It says establishment of a hybrid court to try the individuals might take long, but collection and preservation of evidence must start now.

The crimes were documented in numerous reports, including those of the African Union Commission of Inquiry and the United Nations Office of the High Commission for Human Rights.

They include acts of killings, torture, mutilations, rape and forced cannibalism.

In a statement, Ken Scott, a consultant with Amnesty International says these crimes must be urgently and impartially investigated.

He says all the evidence should be preserved until the hybrid court is established to try the perpetrators.

Amnesty International says this is a first step towards justice and accountability.

The rights group noted that any delay will lead to degradation of physical evidence, or the evidence may even be intentionally destroyed. This would deny justice to the people of South Sudan.

Amnesty International also strongly urged the African Union and the International community to quickly establish the hybrid court, to bring individuals who violated human rights to justice as soon as possible.