Demolition crews on Monday started tearing down a disputed youth center that was at the heart of recent street riots in Copenhagen.

Workers wore face masks under their helmets to conceal their identities as a wrecking ball slammed into the Youth House, a graffiti-sprayed brick building in the Noerrebro district of the Danish capital.

The building for years served as a popular cultural center for anarchists, punk rockers and left-wing groups. The squatters considered it as free public housing, but courts ordered them out after the city sold the building to a Christian congregation.

The building, a former theater, "was a total wreck. It would cost us a fortune to have it fixed," said Ruth Evensen, leader of the small congregation that bought the house in 2001. She said it also posed a fire hazard, and declined to reveal the congregation's plans for the site.

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A police anti-terror squad evicted squatters from the building on Thursday, triggering three nights of clashes with youth that turned parts of the city into a battle zone.

More than 650 people were arrested and at least 25 were injured as protesters hurled cobblestones at riot police and set fire to cars and trash bins in Copenhagen's worst riots in 14 years.

As dust from the demolition filled the air Monday, angry youth yelled obscenities at police who had cordoned off the area around the building. Others hugged and cried.

Local left-wing lawmakers and a construction workers union tried to halt the demolition, citing health hazards caused by dust containing carcinogenic asbestos, but a demolition company representative denied there was any danger.

"They are breaking my heart. I cannot stand it," said Birgitte, a black-clad 21-year-old woman with dreadlocks. She refused to give her last name, saying using one name was the norm among the people frequenting the building.

Helmeted riot police kept a growing crowd of youths at bay at the demolition site, but no violent incidents were reported.

Those arrested in the recent street clashes included foreign activists from Sweden, Norway, Germany and the United States, police said. More than 200 were remanded in custody, while 15 were released. Others were still awaiting court hearings.

The riots were Denmark's worst since May 1993, when police fired into a crowd of rioters protesting the outcome of a European Union referendum. Ten protesters were wounded at the time.

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