Tens of thousands of South Sudanese are fleeing their homes after inter-ethnic clashes around the town of Pibor. The UN is warning villagers to run for their lives as some 6,000 fighters advance on their ethnic rivals. Fighters from the Lou Nuer ethnic group are pursuing members of the Murle community, reports say, as a deadly vendetta over cattle raiding continues. A UN official told the BBC that peacekeepers and government troops are heavily outnumbered. The government is sending additional police and troops in a bid to quell the violence. About 1,000 people have been killed in recent months as reprisal attacks over cattle raids have escalated. Tens of thousands of Murle fled Pibor after it came under attack from the Lou Nuer on Saturday. BBC East Africa correspondent Will Ross says the Lou Nuer are attacking villages and burning homes and that it could take a week for the Murle to walk to an area of safety. UN deputy humanitarian coordinator in South Sudan Lise Grande told the BBC that several hundred UN peacekeepers and government troops were "far outnumbered" by about 6,000 Lou Nuer fighters. "Several flanks of the attackers have moved in a south-easterly direction [from Pibor], almost certainly looking for cattle," she said. She said the main part of Pibor had been held but that a clinic belonging to the charity Medecins Sans Frontieres (MSF) had been "overtaken". Full Story:South Sudanese flee to escape deadly ethnic vendettaSource:BBC News