Three teenagers have been assaulted as hundreds of revellers attended a dune party along Victoria's Bellarine Peninsula.
A group of males armed with a knife approached two 16-year-old boys in the dunes at Point Lonsdale after midnight, assaulting them and stealing their mobile phones.
Another male teenager, 17, was assaulted and stabbed by offenders before being taken to hospital non-life threatening injuries.
More than 300 partygoers attended the unregulated Saturday party, advertised on social media, with police including the riot squad called in move on the revellers.
"When you put out an invitation on social media you have no control over who attends and the behaviour of others, as we have seen in this instance," Superintendent Craig Gillard said on Sunday.
"I encourage parents to know where their children are going, especially those underage, validate their claims and help us to reduce the risks to them."
Police will continue to conduct regular patrols in the Point Lonsdale and Queenscliff area over summer.
© AAP 2019