Berlin, May 15(IRNA) Danish police on Tuesday arrested 50 people for their role in street riots in the 'free state Christiania' district of Copenhagen, German news reports said.

Hundreds of protestors erected barricades and set several vehicles on fire late Monday night
At least 12 people were detained and one police officer was injured in the clashes, according to Danish television.

Several anarchist and militant leftist groups took part in the riots which have sparked after authorities announced the demolition of an illegally built house in the Christiania area which has a semi- autonomous status since 1971.

The 800 residents of Christiania and the Danish government are involved in a bitter dispute over the legal position of the alternative community in the free state district.

The Danish capital was also the scene of riots in March when more than 650 people were arrested following the closure of a youth center.

In that time, demonstrators led fierce street battles during several nights of riots in the Danish capital which also spilled over German cities.

Danish protestors set numerous cars and garbage cans on fire and set up street barricades in Copenhagen during March unrest after the riot police and anti-terror units moved in to evict a popular youth center in the Danish capital.

Several people were injured in the street fightings, among them police officers.

The youth center was occupied by mainly radical leftist and anarchist teenagers in 1981 and had meanwhile been sold to a church.

Police had to use tear gas to disperse the rioting crowd who hurled stones, chairs and firecrackers towards security forces.