Thousands of civilians and soldiers loyal to a renegade Muslim leader fled northwestern Bosnia for Serb-held parts of Croatia on Tuesday as government forces crushed remaining resistance, the United Nations said.

Success in the Bihac pocket, where rebel Muslim Fikret Abdic had allied himself with Serbs against the Bosnian government, would be the biggest victory so far for the Bosnian army in 28 months of war.Meanwhile, the international airlift that supplies the besieged Bosnian capital with most of its food resumed Tuesday, 21/2 weeks after it was shut down by sniper fire on relief planes.

At least 5,100 civilians and 1,600 soldiers loyal to Abdic were settled in tents in Serb-held regions of Croatia, spokesman Paul Risley at U.N. headquarters in Zagreb, Croatia, said.

"This would appear to represent the end of Abdic forces as an effective fighting unit," he said.

Abdic broke with the government last year and had been backed by Serb artillery as he sought to carve out a ministate independent of the Bosnian government.

The Bosnian army said in Sarajevo that its troops were closing in on Abdic's stronghold, Velika Kladusa, and predicted it would fall in a few days.

It said it had slowed its advance to allow for a negotiated end to the fighting. Abdic was reported to be negotiating Tuesday with the government in Velika Kladusa.

The Bihac area has been held by Muslims throughout the war. It is surrounded by Serb-held territory in Bosnia and Croatia.