Neo-Nazis trying to march through the Jewish quarter of Prague on Saturday clashed with groups trying to stop them, and at least 80 people were arrested in outbreaks of violence around the capital.
Police seized weapons including a gas gun, axes and sticks as the extremists tried to reach the Jewish quarter, police spokesman Ladislav Bernasek said.
At least six people, including one policeman, suffered head injuries, said Prague rescue service spokeswoman Jirina Ernestova.
The march was scheduled a day after the anniversary of Kristallnacht, the night in 1938 when the Nazis attacked synagogues and Jewish homes and businesses throughout Germany and parts of Austria.
Authorities banned the march, and about 1,400 police were deployed in the capital, including riot police and officers on horses to prevent it. Equipped with armored vehicles and water cannons, they sealed off most of the historic Jewish quarter.
In a major clash downtown, a group of about two dozen neo-Nazis was attacked by people who said they were in the streets to prevent the march, Bernasek said.
About 50 left-wing extremists attacked police with cobble stones in another area.
In total about 80 people were detained around the city, including 10 German-speaking left-wing extremists armed with sticks, Bernasek said.
Jewish leaders and Czech politicians condemned the planned march as an insult to the victims of the Holocaust.
Hundreds of Jews and others gathered in the historic Jewish quarter to commemorate the Nazi pogrom, protest the march and be ready, if it went ahead, to prevent it from going through the neighborhood.
We are here "to protest attempts of neo-Nazi groups to publicly promote anti-Semitic, racist and other abusive ideas," said Jiri Danicek, head of the federation of Jewish communities.
The march was organized by the Young National Democrats, which is linked to the National Resistance, a neo-Nazi group.