Many fear a civil war could reignite between north and south Sudan following the north's recent invasion of a disputed territory.
Southern Sudan is set to become an independent state on July 9, but both the north and south want the city of Abyei within their boundaries.
Leaders in the Christian south believe the Muslim north is planning a "full scale war" in the region.
Northern government troops are currently occupying Abyei, blockading border crossing points into the city.
County Commissioner Dominic Deng said at least 80,000 people have fled Abyei since the invasion last weekend.
U.N. Officials now worry there is not enough food and supplies for Sudanese families leaving for nearby areas.