(CBS/AP) HAREN, Netherlands - Riot police were out in force in a small Dutch town Friday night confronting about 30,000 people who showed up for a girl's 16th birthday party that was inadvertently advertised on Facebook.
Authorities say 34 people were arrested Friday night and in the early hours of Saturday morning as rioters clashed with police in Haren, 115 miles north of Amsterdam.
Police and prosecutors say they are investigating how the rioting erupted.
Mayor Rob Bats said on Saturday: "Scum ran amok in our town."
Dutch media reported that the party originally was planned as a small celebration by a 16-year-old girl. Reports say she failed to mark the invitation as private - and it went viral.
Some of the people arriving in Haren on Friday wore T-shirts emblazoned with "Project X Haren," a reference to the film "Project X" that portrayed an out-of-control party.
Police were forced to move the girl and her family to an undisclosed secret location.
The crowds were not entirely unexpected. After the Facebook invite went viral, "Project X Haren" website and spoof videos announced parties and after-parties. A giant banner was unfurled on the side of a building. Thirty thousand revelers signed up that they planned to attend. One company planned to offer live streaming of the event.
The city prepared by removing street signs, closing off streets and banning alcohol at the train station.