|UN reports suggest that between 26,000 and 30,000 cattle have been stolen [EPA]
Recent tribal clashes and cattle raids in South Sudan have left nearly 600 people dead and hundreds more injured, the United Nations said.
The 600 were reportedly killed in fighting between the Murle and Lou Nuer communities in Jonglei state, the UN said on Monday.
A statement said there were unconfirmed reports of more than 750 people being wounded.
Hilde Johnson, the UN representative in South Sudan, appealed for restraint and said the cycle of violence must stop.
The UN said reports suggested that between 26,000 and 30,000 cattle have been stolen.
Jonglei Governor, Kuol Manyang Juuk, said some villages were destroyed when warriors from the Murle tribe in Pibor county attacked the Lou Nuer tribe on Thursday.
Juuk estimated the death toll at 125.
He said on Friday that women and children were among the dead and that the fighting started in Bier sub-county.
Juuk said Murle tribe members were suspected of attacking five villages of the Lou Nuer. Cattle had been stolen and some women and children abducted, he said.
Local officials in Pibor, which was ravaged by violence in June, estimated that more than 360 members of the Murle ethnic group were killed in raids just weeks before the south declared independence.
The Pibor County government said that 73 women and children were reported missing during the June raids.
South Sudan became independent from Sudan on July 5 to much international fanfare, but diplomats have expressed mounting concerns about stability in the country.
The new country is already reeling from internal violence - often in the form of massive cattle raids - that are devastating communities in the vast swamplands of its eastern region.
Last week's deaths bring to more than 3,000 the number of people killed in hundreds of violent incidents in South Sudan this year.