9News understands the man was a passenger on a Transperth bus on route 998, which goes from near the University of WA to Swancare, at 12pm today (AWST)
Witnesses say the man got on at Morely train station, where he began “bickering” with a woman he seemed to know.
A passenger asked the man to step off the bus when the altercation turned violent, with the man allegedly pulling out an axe and threatening passengers.
One witness told 9news that they felt “very scared” as the situation unfolded.
He was pushed off the bus, before he was captured on camera running towards it wielding the axe.
It’s alleged he hit the vehicle several times before he disappeared into nearby bushland.
Police say they are investigating and are looking for the alleged attacker.