Twenty-seven people were killed in South Sudan's Central Equatoria state in tit-for-tat violence between cattle herders and a members of a militia on the eve of a Friday visit to the country by Pope Francis, a county commissioner said.
The pope is set to arrive in South Sudan from neighbouring Democratic Republic of Congo, hoping to jolt a peace process aimed at ending a decade of conflict fought mostly on ethnic lines that has killed hundreds of thousands of people.
After fighters from a rebel group killed six people from a herding community, herders retaliated on Thursday by killing 21 civilians in a nearby area, including five children and a pregnant woman, said Kajo-Keji county commissioner Phanuel Dumo.
A peace deal signed in 2018 by the main parties to civil war from 2013-2018 has significantly reduced violence in South Sudan in recent years but lower-level clashes between rival communities regularly flare up.
The Archbishop of Canterbury, who is accompanying the pope to South Sudan, said he was horrified by the latest killings.
"It is a story too often heard across South Sudan. I again appeal for a different way: for South Sudan to come together for a just peace," he said on Twitter.