A "Facebook party" that attracted up to 1500 young people in Napier on Saturday was closed down after police arrested 15.
Senior Sergeant Nick Dobson of the Eastern District command centre said police became aware of the party via a Facebook message during the afternoon and monitored the situation in Rutherford Rd, Marewa. Numbers swelled during the evening.
"It was one of those Facebook fiascos," he said.
"It caused an awful lot of problems."
Arrests were thought to have all been for disorderly behaviour as police tried to disperse the crowds, which in some cases retreated to the grounds of nearby Marewa School.
Police closed the party down at about 1.30am.
The street was littered with cans and other rubbish, which was cleared away yesterday.
The party had been heralded on Facebook by what Mr Dobson called a "full, open invite" and was held on a back section.
According to other Facebook posts, it had an entry fee, which covered the cost of a DJ, security and "clean-up", and was the second run by the organisers. Another is planned.
Police weren't impressed.
"It was one of those Facebook fiascos, and I think the security was a few of the guy's mates, with fluorescent stripes on their jackets," said Mr Dobson.
A Rutherford Rd resident, who did not want to be named, described coming home on Saturday night to see "a whole bunch of teenagers, probably 200, on the streets drinking".
"It was rather annoying. The music was just really, really loud. I saw a couple of people get taken away in the police wagon," the resident said.