Children and the disabled in South Sudan have been burned alive and pro-government militia allowed to rape women as a form of payment, a UN report has said, describing what is happening in the country as "one of the most horrendous human rights situations in the world".
"The report contains harrowing accounts of civilians suspected of supporting the opposition, including children and the disabled, killed by being burned alive, suffocated in containers, shot, hanged from trees or cut to pieces," the UN human rights office said in a statement on Friday.
"Credible sources indicate groups allied to the government are being allowed to rape women in lieu of wages but opposition groups and criminal gangs have also been preying on women and girls."
The prevalence of rape "suggests its use in the conflict has become an acceptable practice by (government) SPLA soldiers and affiliated armed militias," the report said.
South Sudan presidential spokesman, Ateny Wek Ateny, denied that groups allied to the government had committed atrocities.
"We tell them to minimise civilian casualties when they are actually forced to fight," he told Al Jazeera.
Al Jazeera's diplomatic editor James Bays, reporting from Geneva, said UN human rights chief Zeid Raad al-Hussein described South Sudan as a crisis that had fallen off the international radar.
The UN report is the work of an assessment team deployed to South Sudan between October and January. It said "state actors" bore the most responsibility for the crimes, and that attacks on civilians, forced disappearances, rape and other violations could amount to war crimes and crimes against humanity.
In South Sudan's oil-rich Unity state, 1,300 rape cases were reported within just five months last year, it said.
The report came as rights group Amnesty International released a separate report detailing how South Sudanese government soldiers killed more than 60 men and boys last October by locking them into a shipping container until they suffocated.
South Sudan has been gripped by violence since December 2013, when a power struggle between President Salva Kiir and his political rival Riek Machar descended into a full-blown conflict. Tens of thousands have been killed and more than 2.3 million displaced.