Polish police clash with protesters on national holiday By Marcin Goettig and Rob Strybel WARSAW (Reuters) - Riot police in the Polish capital used truncheons on Sunday to break up a crowd of right-wing extremists pelting them with firecrackers and lumps of concrete after a parade to mark the national holiday turned violent. Thousands of police had earlier lined the streets of Warsaw to try to stop right-wing nationalists and radical left-wing groups from using the independence day holiday as an opportunity to fight each other. It was the second year the celebrations have degenerated into violence, underlining the deep gulf between those who want a conservative, religious society that rejects foreign influence and those who want Poland to join the European mainstream. As demonstrators gathered for the right-wing rally, young men with their faces covered by scarves chanted nationalist slogans and railed against supposed Jewish conspiracies. "Poland is going in ... the direction of dependency, energy dependency, economic dependency," said one of the demonstrators, who gave his name as Wojciech. The fighting started when some of the right-wing protesters threw firecrackers and projectiles at police in riot gear who had cordoned off the area. A Reuters correspondent saw police respond by beating protesters with truncheons, forcing them to disperse into nearby streets. Some demonstrators tore off chunks of concrete at a construction site to use as missiles. Police used loud-hailers to warn protesters they would use rubber bullets, water cannon and tear gas. Polish President Bronislaw Komorowski, addressing the official independence day parade in Warsaw a few hours before the violence broke out, appealed for a less polarized society. "Today public life is poisoned by excessive rows," he said. We should be critical, but criticism should not mean mutual destruction. On the same date last year, right-wing demonstrators set fire to a television van and fought pitched battles with police who were trying to prevent them attacking a counter-demonstration by left-wing radicals. Poland, the biggest economy in eastern Europe, is experiencing a period of peace and prosperity unusual for a country with such a turbulent history. Prime Minister Donald Tusk, a liberal, is credited by many Poles for bringing political stability. But the predominantly Catholic society is deeply split over issues such as abortion, gay rights and religious tolerance. Most of the time the argument is conducted in reasonably civil terms, though extremists on the margins of each camp often get violent. Writing by Christian Lowe; Editing by Sophie Hares