BUCHAREST, Romania - At first, fans politely applauded the Roma performers sharing a stage with Madonna. Then the pop star condemned widespread discrimination against Roma, or Gypsies — and the cheers gave way to jeers.

The sharp mood change that swept the crowd of 60,000, who had packed a park for Wednesday night's concert, underscores how prejudice against Gypsies remains deeply entrenched across Eastern Europe.

Despite long-standing efforts to stamp out rampant bias, human rights advocates say Roma probably suffer more humiliation and endure more discrimination than any other people group on the continent.