The World Clown Association said it was sick of jokers tarnishing the profession and revealed some of its performers had been quizzed by police following some of the more threatening incidents.
“Whoever is doing this crazy stuff is not a clown,” organisation president Randy Christiansen said.
“This is not clowning.
This is someone trying to use a good, clean, wholesome art form and then distorting it.”
The first incidents were reported in August of clowns trying to lure children into woods in South Carolina in the US.
The trend has spread globally including to Australia.