Thousands of South Sudanese, some of who were forced to eat human flesh or disembowel corpses, are suffering mental illnesses, Amnesty International says in a new report.

Describing South Sudan as “a traumatised nation,” Amnesty found mental disorders to be widespread in interviews it conducted with 161 victims and witnesses of atrocities.

One such survivor, identified as Phillip, said he hid under a pile of dead bodies during a massacre carried out by government forces in the capital Juba in December 2013.

When soldiers discovered him, they “tied my arms behind my back and forced me at gunpoint to drink blood and eat flesh” of those killed, Phillip recounted.

“I can’t eat, I don’t want anything I am offered,” he told Amnesty researchers two years later.

“I don’t think the way I am feeling will ever change.”

No one knows how many South Sudanese have been killed during the civil war that broke out in 2013. Estimates range to 50,000 or higher, with both sides in the conflict said to have slaughtered members of rival tribes.

Thousands more have been raped and tortured, human-rights activists say. About 20 per cent of the country’s 11 million people have been forced to flee their homes.

Government troops have sought to suppress evidence of the number of those they have killed, a survivor relates in the report entitled “Our Hearts Have Gone Dark.”

South Sudan has almost no capacity to treat those suffering from post-traumatic stress disorder, the rights group says.

“As a result of the lack of appropriate services and facilities, people with mental health conditions are routinely housed in prisons, even if they have committed no crime,” Amnesty says.

Researchers found in May, for example, that 82 inmates of Juba Central Prison, including 16 women, were categorised as mentally ill. More than half of them had not been charged with crimes.

“The government, supported by the international community, must honour its international legal commitments to respect, protect and fulfill the right to health, including mental health,” said Muthoni Wanyeki, Amnesty International’s regional director for East Africa.

“ It must also prevent and impartially investigate and prosecute acts such as torture that continue to cause psychological harm to many,” Ms Wanyeki said.

Soldiers electrocuted more than 60 detainees in a facility in Juba in September 2014, a man identified as Lual told Amnesty.

“Whenever they would kill people, we would be taken to dissect the stomachs of those who were killed, so they could be thrown into the river and wouldn’t float,” Lual said.

“Once your stomach is cut, you don’t float, you just rot under the water. Because if you float, your body will litter the river and it will be evidence that people were killed.”

Lual escaped detention after being held for five months, but he cannot leave behind the horrors he experienced.

“I am haunted by the cutting of the stomachs of the victims,” he states in the report.

“I wake up and I can’t go back to sleep. I feel hopeless. I’m not interested in talking to people. I prefer to stay alone… I feel depressed, I am never happy.”

South Sudan has almost no capacity to treat those suffering from post-traumatic stress disorder, the rights group says.

It notes that there are only 12 beds in the psychiatric ward of the sole public hospital providing such care in a country of 11 million people. South Sudan has two practicing psychiatrists, both based in Juba and neither of whom sees patients on a fulltime basis, the report adds.

“As a result of the lack of appropriate services and facilities, people with mental health conditions are routinely housed in prisons, even if they have committed no crime,” said Amnesty.

Researchers found in May, for example, that 82 inmates of Juba Central Prison, including 16 women, were categorised as mentally ill. More than half of them had not been charged with any crime.

The United Nations, which provides shelter to nearly 200,000 civilians at six protected sites around the country, is not equipped to treat all those in need of therapy, the report adds.