Clashes have erupted for a second night between police and youths over the Youth House building in the Noerrebro district of the Danish capital, Copenhagen.
The trouble started on Thursday when the authorities moved in to evict squatters, sparking 217 arrests and the erection of barricades by protesters.
At least 25 people were injured on Thursday in scenes the Danish media described as a war zone.
The violence spread into the evening as activists vowed to take back the youth centre, which was sold to a Christian group in 2000.
The authorities cleaned up wreckage on Friday but extra police were brought in amid fears of more violence.
A second night of violence then brought more than 100 arrests in the Noerrebro and Christianshavn districts.
Protesters threw petrol bombs and set cars alight. Police fear the rest of the weekend could bring more violence.