GENEVA (Reuters) - The African Union is making itself complicit in South Sudan’s bloodshed by failing to set up a court to try atrocities, members of a U.N. human rights investigation said on Tuesday.

South Sudan gained independence in 2011 but collapsed into violence in late 2013 when rivalry between President Salva Kiir and his then-deputy Riek Machar ignited a civil war that has often followed ethnic lines.

Under an August 2015 peace deal, the African Union and South Sudan were supposed to set up a “hybrid court”, based on a mix of their laws, to prosecute suspects who include top political and military figures.

Yasmin Sooka, head of the U.N. commission on human rights in South Sudan, said the court needed to be operational by the end of the year to stop a “massive” increase in gross human rights violations in the past nine months.

“A small coterie of South Sudan’s political leaders show total disregard not just for international human rights norms but for the welfare of their own people. They have squandered the oil wealth and plundered the country’s resources,” she told the U.N. Human Rights Council in Geneva.

“There can be no more delay, no more excuses,” she said. “The alternative is policy of appeasement – making us complicit in the bloodshed that is happening.”

Her colleague Kenneth Scott said the signs were not good.

“There is no reason to think that a robust hybrid court will be set up any time soon by the African Union, if ever. Indeed some senior officials have told us that it will never happen,” he said. “We hope that’s wrong.”

Both the African Union and the South Sudan government had failed to engage with the U.N. commission, he said.

“We’ve requested the draft documents that we understand exist -- a draft statute, a draft memorandum of understanding -– but they have declined to provide it to the commission.”

Many African leaders are suspicious of the Hague-based International Criminal Court and prefer “African solutions” for African problems.

But Sooka said that if South Sudan could not protect its own civilians, the international community must take steps to hold perpetrators to account.

South Sudan’s Justice Minister Paulino Wanawilla Unango told the Council that he didn’t recognize the commission’s portrayal of his country. He said the team had only visited U.N. sites for protecting civilians in four towns and had not reflected the government’s views in its report.

“It will never be a fair investigation,” he said.

As well as famine and ethnic conflict, the war has unleashed an epidemic of rape, uprooted nearly 2 million people within the country and created more than 1.5 million refugees.

A cholera outbreak has spread northwards down the Nile, reaching South Sudan’s second city of Malakal and threatening to continue towards Sudan.

The government “obstructs and manipulates” aid for famine-hit, opposition-controlled areas, risking even greater catastrophe, Sooka said.

The opposition also contributed to the famine by attacking government installations, looting convoys and terrorizing communities suspected of supporting the government or the Dinka tribe, Sooka said.