Around a million people have been forced from their homes and farms in South Sudan's most fertile region, adding to the risk of famine, Amnesty International said Tuesday.
People in the southern Equatoria region have left after being targeted by atrocities committed by both government and opposition forces, the rights group said.
"It is a cruel tragedy of this war that South Sudan's breadbasket -- a region that a year ago could feed millions -- has turned into treacherous killing fields that have forced close to a million to flee in search of safety," Joanne Mariner, Amnesty's senior crisis response adviser, said.
The three-and-a-half-year civil war, which has led to tens of thousands of deaths, had left the region largely unaffected until a year ago, when the fighting turned to Yei, around 150 kilometers (95 miles) southwest of capital Juba.
Around 6 million people in South Sudan are "severely food insecure", according to the UN Office for the Coordination of Humanitarian Affairs. These include 1.7 million on the brink of famine.
Amid a widespread cholera outbreak, more than 2 million are internally displaced, the UN added. Around a million people have fled to neighboring Uganda.
Based on eyewitness reports gathered last month from villages around Yei, Amnesty said government troops have been mostly responsible for crimes and serious human rights abuses, including war crimes, against civilians.
"The escalation of fighting in the Equatoria region has led to increased brutality against civilians," Donatella Rovera, another Amnesty official, said.
"Men, women and children have been shot, hacked to death with machetes and burnt alive in their homes. Women and girls have been gang-raped and abducted.
"Homes, schools, medical facilities and humanitarian organizations' compounds have been looted, vandalized and burnt to the ground. And food is being used as a weapon of war."
Amnesty said rebel fighters had killed civilians deemed to be government supporters -- often for belonging to President Salva Kiir's ethnic group, the Dinka.
The government denied Amnesty's report.
"It is very unfortunate that Amnesty International is giving an unrealistic and misleading report that is not true on the ground," Deputy Information Minister Akol Paul Kordit told Anadolu Agency.
"Hunger or famine is caused by unreliable rainfall and no government in the world could be blamed for that."
