At least 11 people have been shot dead after government and forces loyal to Machar clashed in Goli area of Tore County, Yei River State on Monday.
Yei River State Acting Minister of Information, Huda Micah Laila says the clashes followed series of attacks by SPLA-IO on government positions.
She says the government has formed a committee to investigate the matter.
The minister did not tell whether the eleven persons killed are civilians or forces.
The warring parties signed cessation of hostilities in December 2017, but the parties failed to implement, according to the Joint Monitoring and Evaluation Commission or JMEC Chairperson Festus Mogae.
However Yei River State Minister of Information insists that the government is committed to peace, accusing the IO of breaking the agreement.
Radio Easter could not reach SPLA in opposition to confirm the allegation.