Over 150,000 people have fled violence ravaging Sudan\'s contested Abyei border region and surrounding areas, a southern Sudanese minister said on Friday. \"The situation is terrible - over 150,000 have fled Abyei and the areas around,\" humanitarian affairs minister James Kok Ruea said. Northern troops overran the fertile border region last week drawing condemnation from world powers who have warned the action is a threat to peace between north and south. \"Women, children, elderly - they are running in fear from brutal violence, without shelter,\" Ruea said, before setting off to assess the affected areas. The figure is a huge leap from earlier UN estimates but those figures were based on the number of people who have actually been counted. Hiding Many of those fleeing are believed to be travelling off the main roads and hiding in surrounding bushes for fear of attack by northern aircraft. \"Large numbers of people continue to move on bush paths,\" a UN assessment report released Friday read. It said it was unclear how many of the estimated 110,000 residents of Abyei had fled south. Air and ground patrols searching for people fleeing found no trace in Abyei, indicating the area is empty except for a \"heavy presence of armed men,\" it noted. \"The air assessment mission flew over 10 villages north and south of Abyei town,\" the report said. \"No displaced populations were observed... burnt tukuls (thatch huts) in several villages were reported.\" UN estimates are conservative as reports of new arrivals continue. \"As of 26 May, humanitarian partners estimate that more than 30,000 people have made their way south,\" it said. Abyei\'s future is the most sensitive of a raft of issues that the two sides had been struggling to reach agreement on before the south\'s full independence in July.