Some 100,000 minority Uzbeks fleeing a purge by mobs of Kygryz massed at the border Monday, an Uzbek leader said, as the deadliest ethnic violence to hit this Central Asian nation in decades left entire blocks of a major city burned to the ground.

As the southern city of Osh smoldered for a fourth day Monday, the official death toll of 117 killed and 1,500 injured from the clashes that began Thursday appeared way too low.

An Uzbek community leader claimed at least 200 Uzbeks alone had already been buried, and the International Committee of the Red Cross has said its delegates saw about 100 bodies being buried in just one cemetery.

The United States, Russia and the United Nations worked on humanitarian aid airlifts while neighboring Uzbekistan hastily set up refugee camps to handle the flood of refugees, many of whom Uzbekistan said had gunshot wounds.

Jallahitdin Jalilatdinov, who heads the Uzbek National Center, told The Associated Press on Monday that at least 100,000 Uzbeks had fled for the border and were awaiting entry into Uzbekistan, while 80,000 had already crossed.