Khartoum — Authorities' failure to prosecute or remove suspected war criminals has been blamed for the murder of civilians, rape of women and girls as well as looting and destruction by government troops and militia in South Sudan.
The violations have continued unabated over the past five years after the country spilled into civil war as a result of a fallout between its leaders.
"A key factor in this brutal offensive was the failure to bring to justice those responsible for previous waves of violence targeting civilians in the region," said Joan Nyanyuki, Regional Director for East Africa at Amnesty International.
The human rights activist said Leer and Mayendit provinces had been hardest hit in the past yet the South Sudanese government continued giving suspected perpetrators free rein to commit fresh atrocities. "The result has been catastrophic for civilians," Nyanyuki said.
The government of President Salva Kiir has been urged to end the impunity enjoyed by South Sudanese fighters on all sides.
"The government must ensure that civilians are protected and that those responsible for such heinous crimes are held to account," Nyanyuki said.
The human rights group also appealed to the United Nations Security Council to enforce the arms embargo adopted in July.
South Sudan, with a population of more than 12 million people, is the world's newest country after attaining independence from Sudan in 2011.