Police are investigating a violent brawl in Perth’s northern suburbs that involved dozens of students spilling out onto a busy road - before attacking a parent.

Video of the violence outside Butler College has been sent to police who want to speak to anyone who witnessed or was involved in the shocking melee.

The footage shows a number of fights breaking out between students, with some being dragged across the road in front of passing traffic.

Investigators have been told that a number of adults were also involved in the brawl, but aren’t believed to have been hitting students.

A mother, believed to have stepped in to stop the brawl, can be seen being pinned up against a car and punched in the shocking footage.

The incident, which happened at about 3.30pm yesterday, didn’t take place on school grounds but students have been warned that if they are found to have been involved could face suspensions of up to 10 days.