Clashes have broken out in Warsaw between hooligans and police amid celebrations of Poland's Independence Day.

Polish media broadcast scenes of youth, some masked, throwing rocks, firecrackers and cobble stones at police on Tuesday. In one case police turned a water cannon against the protesters.

The rioters haven't given any reason for the violence, which has turned into a yearly ritual on the Polish public holiday in recent years.

Police said they have arrested several people who attacked officers, but wouldn't specify how many.

Earlier, President Bronislaw Komorowski led official celebrations and a march for the holiday, which celebrates Poland regaining its independence after World War I.

For the 123 years before that Poland was effectively wiped off the map, partitioned by Austria, Russia and the German kingdom of Prussia.