Police received information just before 9:30pm, of groups of young people heading to a party in the Mandurah area.
Police on patrol attended a residence in Dudley Park and observed a group of more than 100 youths at the home.
At the time there were only two adults present.
Based on the amount of supervision on the group, it was deemed the party was likely to become out of control at which point the party was closed down and the youths were moved on.
A few members of the group allegedly started to throw projectiles at police, and several fights broke out amongst the teens.
As a result, one juvenile will be charged by summons for failing to comply with an order, while three other juveniles were issued with juvenile cautions for disorderly behaviour.
An additional two juveniles were taken into police care and conveyed home.