South Sudan soldiers are being blamed for the deaths of up to 23 civilians in two separate regions in the world's newest country.
A South Sudanese official said Tuesday that the first incident took place in Jonglei state last week. The official said soldiers rounded up civilians and fired on the group, killing 13. The official spoke on condition of anonymity because he was not authorized to speak to the press.
The United Nations Mission in South Sudan, UNMISS, says it is investigating the incident.
"We are aware of the reports and we are looking into them," said UNMISS communications chief Liam McDowall.
Jonglei's Pibor County has been at the scene of recent clashes between rebel militias led by David Yauyau and South Sudanese forces. A former member of the South Sudanese army, Yauyau launched his rebellion after failing to win a parliamentary seat in the Sudanese general elections in April 2010.
South Sudan's army - the SPLA - blames Yauyau's forces for the deaths in Pibor. An SPLA spokesman, Col. Kella Kueth said: "The civilians were killed by Yauyau himself," but added that if the SPLA was responsible "it must be people that belonged to Yauyau. How do you categorize people that are not in uniform?"
Kueth repeated the frequent South Sudan accusation that Yauyau's forces are being supplied by Sudan through aerial supply drops in the northeastern part of Jonglei's Akobo county, near the border with Ethiopia.
Separately, SPLA troops were reported to have opened fire on civilians in Western Equatoria state on Saturday and Sunday. The U.N. spokesman, McDowall, said the U.N. mission can confirm that nine people were killed during the two days of violence. Kueth referred questions to the information minister, who did not answer calls seeking comment.