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.
Around 30,000 people reportedly signed up for the party on Facebook and the girl’s family actually went into hiding, as the town, which has a population of 18,000, braced itself for the onslaught of party goers.
Police estimate around 3,000 people arrived in the town on Friday night to attend the party.
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.
Revellers could be seen wearing T-shirts marked “Project X Haren” after Project X – a film released earlier this year about a party that grows out of control.
Such T-shirts had been selling on the internet for 23 euros (£18) apiece. Some featured a crude logo of a man on all fours drinking from a bottle, according to reports.
A new Facebook page has since been created called “Project Clean-X Haren” to clear up after Friday night’s disturbances. It had more than 23,000 “likes” by Saturday.