The U.N, refugee agency says 29 people reportedly were killed and another 10 seriously wounded in what it calls an unprecedented attack on a camp for thousands of internally displaced persons in Sudan's West Darfur region.

A UNHCR spokeswoman, Helene Caux, tells VOA this is the first time since war erupted in Darfur two years ago that a camp for internally displaced people has been directly attacked.

She says a group of 250 to 300 armed Arab men on horses and camels attacked Aro Sharow camp, in northern West Darfur on Wednesday. Ms. Caux says the attackers destroyed part of the camp, burning about 80 makeshift shelters.

"As far as we know, most of the IDP's [internally displaced persons] from the camp have fled the camp to the nearby mountains of the Jebel Moon," she said. "This area is mainly held by the rebel movements who emerged in 2003 and who have been basically fomenting different attacks in the area."

The Jebel Moon area around Aro Sharow has been a no-go zone for the United Nations for several months because of continuing insecurity. Many residents from the region had earlier fled to the Chad border in 2003-2004, then returned to Jebel Moon in May 2004 following a government-announced peace agreement.

Aid workers familiar with the region say the residents, for safety reasons, used to stay at night in the camp that was attacked, but would return to their nearby villages during the day to cultivate their fields.

Ms. Caux says security in Darfur is deteriorating. She says the international community will not be able to continue to provide assistance to the millions of people in need if aid workers do not feel safe.

She says the UNHCR also is afraid people will flee the country if attacks persist and humanitarian assistance is cut off.

"If people in camps do not even feel safe in a camp, they might think of going somewhere else and this would be, of course, a problem to Chad which is a neighbor, the closest country to Darfur," explained Ms. Caux. "There are already 200,000 refugees from Darfur in Chad camps and Chad is already a very poor country and has already shown a lot of hospitality to welcome these refugees and it would be a real problem if more refugees were to go to Chad."

Tens of thousands of people have been killed and about two million have been made homeless during the conflict in Darfur.

Ms. Caux says a UNHCR team will be going to the region where the attack took place on Friday morning to investigate the situation.