A man has been caught on video deliberately riding a motorbike into the path of junior football players at Rushton Park in Mandurah.
It is believed to have happened around 5pm on Thursday during a training session.
The video shows the man riding dangerously close to players at high speed before leaving the scene.
A witness told West Coast Radio the man later came back in his car and tried to enter the field but couldn't due to a chain blocking the entrance.
The incident was reported to police but the man had already left the scene before they arrived.
Anyone who can identify the man should contact Crime Stoppers on 1800 333 000.
WA Police have been contacted for comment.
Postman injured in Wannanup crash
South West resort receptionist charged with 32 fraud offences
Daughter of Port Kennedy hit-and-run victim pleads for offenders to hand themselves in
Concerns for missing woman last seen in Mandurah
Mandurah woman wanted for questioning over current investigation
Investigation underway into Bunbury sexual assault
Two motorcyclists seriously injured in separate crashes
Miraculous escape for two men after plane goes down south of Mandurah
Baldivis family left devastated after rescue shelter takes back adopted dog due to breach of contract