In a report, it said civilians were gang-raped, detained, and children were recruited into militias.

The report - by the UN’s peacekeeping mission in South Sudan (Unmiss) and the UN Human Rights Office - added that at least 64 civilians were subjected to sexual violence, among them a 13-year-old girl who was gang-raped to death.

"I saw the incident with my eyes and it was a horrible scene,” the report quoted a teacher as saying.

The violence in Tambura in Western Equatoria State occurred between June and September 2021.

Some 80,000 people were forced to flee their homes to escape the fighting, the report added.

It named members of the military, fighters from the Sudan People’s Liberation Movement/Army in Opposition (SPLM/A-IO), and militias affiliated to them as being responsible for the human rights violations..

The report added that they included high-ranking military officials and community and religious leaders.

The UN’s High Commissioner for Human Rights Michelle Bachelet called for those responsible to be held to account.