Hundreds of people may have been killed following fighting in Jonglei state, north-eastern South Sudan, local officials say.
Among those confirmed dead is an aid worker from Médecins Sans Frontières (MSF).
Fighting between pastoralists and farming communities in Pieri town erupted last Saturday, displacing thousands of people who fled to the bush.
Dozens of homes were burnt down while warehouses belonging to humanitarian agencies were raided and looted.
Women and children were also abducted and herds of cattle stolen.
Security agencies say they have recovered hundreds of illegal firearms including rifles, rocket-propelled grenades and hand grenades from the warring communities.
Local authorities say they are assessing the number of people killed but believe it’s in the hundreds since the fresh wave of revenge attacks began in February.
The UN’s radio station in South Sudan reports that about 1,000 people have died in the violence but this has not been confirmed.
Violence has erupted several times in Jonglei state, displacing tens of thousands of residents who are already facing starvation and malnutrition.
In February, rivals President Salva Kiir and rebel leader Riek Machar formed a government of national unity aimed at ending six years of a bloody civil war.
But inter-ethnic clashes like this have continued, threatening the fragile peace deal.