Police have been pelted with bottles and fireworks during a riot after a massive Facebook-organised party called "mayhem" in an unoccupied Melbourne home.
Up to 400 teenagers clashed with police after partygoers set off fireworks and gatecrashers showed up at the Glen Waverley house.
About 700 people had been invited to the party, mostly through Facebook, according to a group of youths who returned to the house on Saturday.
"They called it mayhem," one teenager said of the Facebook invite.
"It's also written inside on the walls."
The youths, who didn't provide their full names, say there may be "mayhem round two".
Neighbours said the event had been advertised on Facebook as an end of year 12 and Halloween party.
People were lining up to get into Friday's party and were being charged for entry, before gatecrashers turned up about 11pm, the youths said.
"The guy who was hosting the party ran screaming there's a gang trying to get in by the back," a neighbour, who did not want to be named, told AAP.
Police officers that were first on the scene had to wait for back up to deal with a massive crowd throwing bottles and fireworks at them.
A police spokeswoman says 70 officers had to be called in to shut the party down, but not before rampaging youths jumped on the bonnet and roof of two police cars.
The youths damaged gardens, fences and a house under construction in the street during the melee, she said.
Some cars were also damaged as riot police pushed the youths up the street to get them to leave.
The youths say the party was well organised, with only people whose names were on a list at the door allowed in.
The six teenagers say the organisers had permission to stage the party and the owner of the house was there at one stage.
No one has lived in the house for about three years and it is set to be demolished.
Party organisers even cleaned up the rundown property in preparation for the party and had the power turned back on, neighbours said.
"They knew that the house was being demolished so it didn't matter how much damage was going to be done," the woman said.
One teenage girl was taken to hospital and two men were arrested for drunkenness.