Several Perth southern suburbs have been earmarked as locations for a 'clown purge' stunt scheduled to take place on Saturday night.
According to the Clown Purge Australia Facebook page, more than 20,000 clowns have been invited to take part in the disturbing trend, likely linked to the release of horror film It which began airing in Australian cinemas on September 7.
Clowns are expected to place red balloons in meeting areas around Mandurah, Cockburn, Rockingham, Kwinana, Aubin Grove and Bullcreek.
"We do not mean harm, all of it is just for a scare and some laughs," the Clown Purge Australia Facebook page posted on Wednesday.
Police have warned participants there is a fine line between a harmless prank and a criminal offence, while some locals are vowing to attack those who dress up as clowns.
Earlier in the year, a 19-year-old man became the first person in WA to be convicted over the 'clown purge craze' after he admitted chasing a group of teenage girls near a shopping centre in October 2016.
Lane Harley pleaded guilty to possessing a disguise and disorderly behaviour over the incident.
He was given a six month good behaviour bond with the clown suit ordered to be destroyed.