Thousands of people have rallied in Bratislava against what they call an "Islamization of Europe" and to oppose a European Union plan for member states to share the burden of hosting a surge of asylum-seekers.

Police say some 300 protesters attacked spectators of a cycle race and clashed with police later Saturday. The City Downhill World Tour Bratislava 2015 race had to be interrupted.

The protesters, mainly right-wing extremists, also tried to attack a smaller demonstration in favor of hosting refugees.

Police spokeswoman Tatiana Kurucova said dozens were detained while three officers suffered injuries.

The protesters condemned an EU plan to divide up refugees arriving largely in Italy and Greece between member states.

Slovakia is expected to accept 785, although the government opposes it.