(CNN) -- The United Nations is deploying peacekeeping troops to the remote town of Pibor in South Sudan, saying it faces an imminent attack by thousands of fighters engaged in ethnic clashes in the war-torn region.
Ethnic tensions in the South Sudan state of Jonglei have been inflamed by tribes fighting over grazing lands and water rights -- disagreements that have dissolved into a number of cattle raids during which women and children were abducted.
About 6,000 members of the Lou Nuer tribe are marching on Pibor, home to the Murle tribe, said Lise Grande, the U.N. deputy humanitarian coordinator for South Sudan. An advance group of about 500 fighters have taken up positions outside the town, she said Friday.
"We deemed that there was a very serious risk to civilians (and) in support of the government of South Sudan's primary responsibility to protect civilians, we have gone ahead and deployed a battalion-size force in Pibor with the aim of deterring violence and helping the government to protect its own people," she said.
The deployment of peacekeeping troops follows reports earlier this week that Lou Nuer fighters raided the town of Lukangol, burning it to the ground and forcing thousands to flee toward Pibor.
"We are so alarmed by the situation that during the course of the afternoon we have reinforced our positions in Pibor," Grande said.
She said the deployment of peacekeepers was to support Sudan's army, which has also taken up in the town.
South Sudan's vice president, Riek Machar, is leading an initiative to bridge the differences between the Lou Nuer and Murle tribes, including encouraging the armed groups to disband and go home, Grande said.
The violence in Jonglei state is the latest to rock South Sudan, which officially gained its statehood in July after separating from the north.
Fighting erupted between Sudan's army and South Sudan rebels in Southern Kordofan even before independence was formalized. The violence has since spread to other areas.
Within a few months, refugee camps filled as fighting in the border states of Southern Kordofan and Blue Nile intensified, displacing an estimated 400,000 people, according to the United Nations and aid agencies, such as Medicins Sans Frontieres (MSF) or Doctors Without Borders.
That, in addition to the crisis in the Darfur region -- where war broke out in 2003 -- qualifies Sudan as one of the world's largest humanitarian crises, according to the United Nations.