The U.N. refugee agency says some 100,000 people have fled tension around the disputed South Sudan town of Abyei.
A spokesman for the U.N. High Commissioner for Refugees says aid workers have received reports of looting and civilians being harassed by armed men.
Adrian Edwards told reporters in Geneva on Tuesday that many of the displaced are still hiding in the bush amid heavy military in the region.
UNICEF spokeswoman Marixie Mercado says about 50,000 of the displaced are children.
North and South Sudan both claim Abyei as part of their territory ahead of South Sudan's formal independence on July 9.