The number of refugees worldwide is at a 25-year low, but a growing number of displaced people are suffering under tighter asylum restrictions and increased fears of terrorism, the U.N. Refugee Agency said Wednesday.

Fewer armed conflicts and large-scale repatriations to countries such as Afghanistan and Sierra Leone reduced the number of refugees to 9.2 million in 2004, compared with 18 million in 1992, according to the U.N.'s "State of the World's Refugees: Human Displacement in the New Millennium."

But growing numbers of displaced people who fall outside the protections of the U.N. Refugee Convention — an estimated 175 million — are facing precarious futures amid increased security threats, growing intolerance and dips in donations, said Antonio Guterres, the U.N. High Commissioner for Refugees.

"Everyone that needs to be protected, should be protected," Guterres said, promising sweeping reforms in the U.N. agency to tackle the growing problems of displaced people.

Chad and Sudan were of particular concern.

Decades of tribal clashes over land and water in Sudan erupted into large-scale violence in early 2003, when ethnic African tribes took up arms, accusing the Arab-dominated central government of neglect. The government has been accused of responding by unleashing Arab tribal militias known as Janjaweed to murder and rape civilians and lay waste to villages — a charge it denies.

More than 180,000 people have died — most from disease and hunger — and millions more have been displaced. Some have moved to neighboring Chad, where the spreading conflict represents a grave security concern.

"We are really very concerned," Guterres said, pleading for more international support. "The whole region is very unstable."

Last year, Sudan and the Democratic Republic of Congo accounted for about 7.5 million of the world's internally displaced people — or people who are not generally considered refugees because they are fleeing an area of their homeland or territory.

While more than 4 million people have been repatriated to Afghanistan and hundreds of thousands more to Angola, Sierra Leone and Liberia, south Sudan could see more than 4 million internally displaced and refugees return in the next few years, the U.N. report said.

Guterres said getting humanitarian assistance to displaced people had been the international community's "biggest failure."

The U.N. report came as asylum seekers in a London detention center entered the 11th day of a hunger strike meant to protest the length and conditions of their detentions. Seven of the 118 asylum seekers were still on strike Wednesday. Most were African and Turkish.

While detentions and anti-terrorism legislation in the United States remained a concern for the U.N. refugee agency, the rate of recognition for asylum seekers in the United States was still higher than European nations, Guterres said, calling for a common EU asylum system.

Guterres said Iraq remained a country of concern. That country's lack of security has forced the United Nations to withdraw its international staff.

More governments also have tightened asylum restrictions since the Sept. 11 terror attacks, leading to more people being turned away despite legitimate concerns.

"Refugees are not terrorists," Guterres said. "They are often the first victims of terrorism."