Cumbria Police have issued a warning to social media users after around 400 people turned up to a 15th birthday party in Egremont.
Police believe that the uninvited youths turned up after seeing the party publicised on a social media site.
Officers were called to Market Hall in Egremont at around 7pm on Saturday night (11th May), after reports that a large group of youths were drinking in the street and causing a disturbance.
The party organisers had expected around 150 guests to attend.
Police spent several hours dealing with the incident, with some youngsters throwing bottles at passing cars.
A large amount of alcohol was recovered from people who were aged under the age of 18, and many had to be taken home as they were in a "drunk and incapable state."