As a spate of sightings of 'creepy clowns' occur across the USA and now the UK, professional clowns are reacting angrily to their craft being used to scare innocent bystanders. Police in the UK have said that those participating in the craze are "tying up police resources".

On their Facebook page, the World Clown Association said: "We stand against any type of terrorism, threats of violence, or bullying (which these mask-wearers are perpetuating)."

"We are proud to promote caring, funny, friendly, g-rated, uplifting, wholesome entertainment as part of the World Clown Association."

Andrew Davis of the World Clown Association described anyone involved in the craze as "an idiot dressed up in a mask". Speaking to the BBC he said: "A genuine clown would not run up to somebody and make them jump and frighten them."

Davis also said that he was "disappointed" people felt like scaring others was "the easiest way they can get a cheap thrill". Davis said that these incidents often take place around Halloween.

Even famed horror writer Stephen King, who wrote the novel IT about a murderous clown, took to Twitter to say it was "time to cool the clown hysteria".

Benjamin Webb, a spokesperson for Angels Fancy Dress, a 175 year old costume supplier based on London's Shaftesbury Avenue, told IBTimes UK that there had been in a spike in sales of scary clown costumes recently but that it was not notable: "clown costumes, scary or otherwise, tend to be very popular in the run up to Halloween."

Webb noted that certain other suppliers tend to "like whipping up a frenzy" around certain controversial costumes but that Halloween should just be seen as an "opportunity to dress up and indulge in escapism".