The Bush administration has authorized a waiver of immigration rules to allow the resettlement in the United States of several thousand Burmese refugees of the Karen ethnic group, now housed in Thailand. The decision came amid reports of a new exodus of refugees after renewed fighting between Burmese forces and Karen rebels.

The decision confirmed by the State Department could mean a new life in the United States for several thousand Karen refugees who have languished, in some case for years, in an encampment in Thailand near the Burmese border.

Until a decision by Secretary of State Condoleezza Rice Wednesday to invoke a special waver of resettlement rules, the refugees had been barred from coming to the United States because of their support for the Karen National Union (KNU), a rebel group fighting the Burmese government.

The Karen refugees had been snagged by a provision of the anti-terrorist U.S. Patriot Act and a related law barring entry to anyone providing material support to a terrorist or armed rebel group.

At a news briefing, State Department Spokesman Sean McCormack said as many as 9,300 Karen refugees at the Tham Hin camp in Thailand could be affected by the decision, but that actual combatants or members of the Karen National Union would not be eligible:

"This waiver is not a guarantee that individuals might be resettled in the United States, but merely something that allows the Department of Homeland Security to consider them as potentially eligible, even though they might be considered under the law to have provided what is referred to as material support, which is the term under the law," he said.

The waiver granted by Secretary Rice is narrowly focused and does not apply to other Karen refugees in the region, or refugees of other nationalities whose bids to enter the United States have been blocked by the same technicalities.

Refugee advocate groups, including Refugees International, have welcomed the U.S. waiver as a breakthrough, albeit a limited one.

News reports say several thousand more Karen refugees have fled Burma for Thailand in recent weeks after renewed fighting between forces of the Burmese military junta and the rebels.

The Karen have been fighting the Rangoon government for decades in a quest for autonomy and the new fighting came despite a truce accord reached two years ago.

The New York-based group Human Rights Watch said Wednesday the U.N. Security Council should urgently respond to the Burmese military drive, which it said has displaced more than 10,000 villagers since November.

Human Rights Watch said Burmese civilians seeking refuge in Thailand have been put at grave risk by landmines planted by the Burmese army along the border.