Mandurah Detectives are seeking witnesses to an incident on a TransPerth bus in Secret Harbour on Wednesday.
It’s understood a man committed an indecent act on the bus while on route 558 between 9:30am, and 10:30am.
Mandurah Detectives said they were investigating the incident.
“The matter has only recently been reported, so we are still chasing CCTV footage but until that arrives can you help?” Officers said.
The man has been described as aged between 20 to 30, olive-skinned, unshaven with bad teeth and was wearing grey sweatpants and top.
TransPerth’s 558 bus is a popular service often used by schoolchildren and seniors as it travels through several suburbs between Mandurah and Rockingham stations.
Anyone with information, or may have witnessed the incident, is urged to contact Crimestoppers on 1800 333 000 or Mandurah Detectives on (08) 9531 8888 and quote reference number IR 300720 1710 11972.