Police car damaged at wild WA party

An unattended police car has been damaged outside a commercial building in Perth's south where up to 250 people gathered for a wild party that was advertised on Facebook.

An out-of-control gathering was declared just before 9pm on Saturday and the crowd was dispersed, with seven move-on notices issued and seven children taken to a safe place.

While police were dispersing the crowd, a police car was damaged on its bonnet, passenger door and side mirror.