At least 74 mine workers have been killed by gunmen in an area south-west of the capital, Juba, with government and opposition officials trading accusations over who was behind the deaths.
The violence occurred over the weekend in mineral-rich Jebel Iraq, which is controlled by the army.
The Sudan People's Liberation Movement in Opposition (SPLM-IO), the party of suspended First-Vice President Riek Machar, condemned the killings, accusing government forces of being responsible.
Paulino Lukudu Obede, acting governor of Central Equatoria state, which includes Jebel Iraq, said the government was "shocked and outraged" by the "brutal and barbaric killing of innocent civilians by rebel forces".
Obede did not say which group had carried out the attacks.
