At least 24 people have been killed in clashes in the troubled southern Sudanese state of Jonglei in recent days, a military spokesman said on Friday.
Fighting first broke out on Monday in the Nuer settlement of Koul-Anyang after a quarrel between two men, but soon escalated and led to the deaths of nine people, said Major General Kuol Diem Kuol.
"It was a normal quarrel between two people, but each of their villages became involved," said Kuol of the southern Sudan Peoples' Liberation Army (SPLA), adding that it took place in the New Fangak region of Jonglei.
"Then fighting began again on the Thursday, and this time it was more bloody," he said, adding that while originally between people from the Nuer ethnic group, the fighting later drew in Dinka people who supported one side.
"From the fighting on Thursday, we have information that 15 Nuer were killed, 16 were wounded and there are five more who are missing," Kuol said.
He said he believed the death toll would rise.
"We are waiting for reliable reports as to the number of deaths from the other side, but there are sure to be casualties there too," he told AFP.
Clashes between rival ethnic groups in south Sudan erupt frequently -- often sparked by cattle rustling and disputes over natural resources, while others are retaliation for previous attacks.
However, a string of recent raids has shocked many, with an apparent sharp increase in the number of attacks on women and children, as well as the targeting of homesteads.
Some 140 people have been killed during clashes in the south's Warrap state this month.
Earlier this month, the United Nations expressed concern at the flare-up of violence in southern Sudan.
Ashraf Qazi, head of the UN mission in Sudan, urged the south's regional government "to investigate these incidents and to redouble their efforts to help de-escalate the rising wave of violence in southern Sudan."
In 2009, some 2,500 people were killed and 350,000 fled their homes -- a higher death toll than in the troubled western region of Darfur.
"The situation is now calm, and there are SPLA troops there to control the situation," Kuol added.
Ten aid agencies warned in a report earlier this month that Sudan could plunge into fresh turmoil if the world community fails to salvage the North-South Comprehensive Peace Agreement (CPA).
The landmark deal ended a 22-year war between the mainly Muslim north and the oil-rich but grossly underdeveloped south, where most people are Christian or follow traditional religions.
Some two million people died and four million were forced from their homes during the war, a complex conflict fought over resources, oil, ideology, ethnicity and religion.
The CPA is meant to pave the way in April for Sudan's first multi-party elections in 24 years, with parliamentary and regional ballots held alongside a presidential vote, ahead of a referendum for the south's potential full independence slated for January 2011.