West Yorkshire Police today warned that what some view as a prank could have “serious unforeseen circumstances”.
Dozens of incidents have been reported across the region so far this week as people continue to dress as clowns and try to frighten others.
And yesterday the panic spreading on social media led to speculation that a 78-year-old man’s fatal heart attack in Leeds was linked to the clown craze.
Police quashed those rumours, saying the man had commented about the behaviour of three men – one of whom had an Incredible Hulk mask – earlier in the day and fell ill later.
Assistant Chief Constable Mark Milsom said: “We are becoming increasingly concerned about the current clown craze involving people dressing up as clowns to try and frighten others.
“West Yorkshire Police are continuing to receive reports of “clown incidents”. Public safety is our priority and we are concerned that one of these incidents may lead to a young or elderly person being harmed, possibly seriously injured.
“While some might view this as a prank there is potential for serious unforeseen consequences. We wish to highlight this concern publicly to perpetrators and encourage them to act more responsibly.”
He said the force would take robust action to arrest and prosecute in cases where they considered criminal offences had taken place.
South Yorkshire Police yesterday said it had received 61 calls about incidents involving people dressed as clowns since September 21.
There were 11 reports in Doncaster, 10 in Barnsley, 18 in Rotherham, 21 in Sheffield and one about a Facebook page.
The incidents include people being dressed as clowns knocking on windows and doors, and children and adults being frightened.
There have also been two reports of clowns with knives, which are being investigated by police.
Terrifying footage has emerged of the moment a clown walked into the path of a driver in Rotherham and stood waving in the middle of a dark road – before running AT the car.
Superintendent Colin McFarlane, of South Yorkshire Police, said: “There is a clear distinction to be drawn between young people who might be dressing up as we move into the Guy Fawkes and Halloween period and those that are dressing as clowns in order to commit public order offences or harassment.
“Clearly those that are crossing the threshold of criminality and especially if they are carrying weapons will be dealt with accordingly. I need people to understand that consequences of their actions and to take responsibility for them - South Yorkshire Police will not tolerate criminal behaviour.
Meanwhile, North Yorkshire Police received eight calls on Monday night alone.
Last night youths dressed as clowns, including one carrying what appeared to be a knife, chased a group of girls in Whitley Bridge, near Selby.
Two masked youths, one of which was carrying a baseball bat, frightened two 11-year-old boys near Westfield Primary School in York.
Humberside Police said it had received a small number of calls on Monday
Superintendent Dave Hall said: “The vast majority of the reports received have either been hoax calls – with laughter clearly audible during the call – messages posted on social media, or simply sightings of people wearing clown costumes, with no suggestion of intimidation or any threats being made, so we don’t want people to be unduly concerned.
“However, we have had a small number of incidents where individuals have jumped out at passersby or knocked on doors or windows.
“It is thought the majority of those involved are children or youths, but this behaviour is no laughing matter. It’s a waste of police time and has the potential to really frighten people – especially the elderly and young children.”