Police and prosecutors are investigating how rioting erupted after thousands of revellers descended on a small Dutch town for a party that was inadvertently advertised on Facebook.
Authorities say 34 people were arrested overnight as rioters clashed with police in Haren, 115 miles north of Amsterdam.
Mayor Rob Bats said: "Scum ran amok in our town."
Dutch media reported that the party was originally planned as a small celebration by a 16-year-old girl but her invitation went viral when she posted it on Facebook.
Some of the people arriving in Haren on Friday night wore T-shirts emblazoned with "Project X Haren", a reference to the film Project X that portrayed an out-of-control party.
Mr Bats said: "An innocent invitation on Facebook for a party led to serious rioting, destruction, plundering, arson and injuries in the middle of Haren."
He said an initial analysis showed a core group of rioters "were very violent and well-prepared and deliberately sought confrontation" with hundreds of police who had been dispatched to the town amid fears of trouble.
On Saturday another Facebook group sprang up called Project Clean-X Haren, urging people to help clear up the debris littering the town's streets.