The United Nations refugee agency (UNHCR) says about 4,000 people fled from Liberia to Sierra Leone after rebels attacked a refugee camp in Liberia late last week. The agency said thousands of others fled into the bush.

The U.N. refugee agency said it is concerned about the condition and whereabouts of thousands of Sierra Leone refugees and displaced Liberians who fled the Sinje refugee camp after it was attacked by rebels.

The camp, about 80 kilometers northwest of the capital, Monrovia, was home to 24,000 people.

UNHCR spokesman Kris Janowski said an estimated 4,000 ran across the border into neighboring Sierra Leone, thousands of others probably fled into the surrounding forest, and several hundred walked to Monrovia.

"But there are still a lot of people, both Sierra Leone refugees who had been residing in Liberia and locally displaced Liberians, who are in that very, very volatile area. Nobody knows, of course, who controls the area around the Sinje camp now. It could still be the rebels. It could be nobody. We know that the camp where these people had lived has been looted and ripped apart. Basically, everything valuable has been taken away," Mr. Janowski said.

Mr. Janowski said refugees arriving in Monrovia are being transferred to one of the existing camps in the capital. He said the thousands of Sierra Leonians and Liberians who managed to cross the border to Sierra Leone report the main highway is not safe. They say thousands of people are hiding in the forest, trying to find a way to safety.

Mr. Janowski also said the agency is worried about five nurses who were abducted in a UNHCR ambulance by rebels who attacked the Sinje camp. He said the UNHCR has had no contact with the nurses since rebels of the group Liberians United for Reconciliation and Democracy kidnapped them on Thursday.