Image copyright AFP Image caption Creepy clowns have been terrifying people on both sides of the Atlantic - but how scared should we be?

It is the craze which is terrifying children and adults alike on both sides of the Atlantic, whether you like it or not.

Creepy clowns, lurking in dark corners, wielding the odd weapon, have closed schools, created mass panic and kept police officers in the US and UK busy.

If you saw one lurking outside your window, you'd have good reason to be terrified.

But just how dangerous are these red-nosed children's entertainers really?

Popular culture - from Batman's The Joker to Pennywise in Stephen King's It - certainly suggests the children's party favourites do give us something to fear.

And, to be fair, history does have its share of killer clowns.

The mass murderer

The most notorious - by a long way - was John Wayne Gacy, otherwise known as Pogo the Clown - or, later, the Killer Clown.

Between January 1972 and December 1978, he murdered 33 young men and teenage boys - burying most of them in the crawl space under his house.

Image copyright AP Image caption The most famous murderous clown - appropriately nicknamed "The Killer Clown" - was John Wayne Gacy, executed in 1994 for killing 33 young men and teenage boys in the 70s

At the same time, the twice-married Gacy was appearing as Pogo, the friendly neighbourhood clown, bringing his own brand of humour to parades, children's hospitals and the odd Democratic fundraiser around Illinois.

But the former manager of a fast-food franchise, later executed by lethal injection, doesn't appear to have been dressed as a clown when committing the killings.

What's more, it is undeniable that his other passion - politics - has produced far more murderers over the years.

The smiling shooter

More than a decade later, an actual "clown killer" struck: Marlene Warren was fatally shot by a clown who arrived at her Florida home holding flowers and two balloons.

When Mrs Warren opened the door, the brown-eyed clown shot her before fleeing in an unmarked car.

One of the balloons left behind as the killer made their escape said, "You're the greatest".

Media playback is unsupported on your device Media caption Clown sightings in the UK

More than 25 years later, her murder remains unsolved and the identity of the gunman behind the white mask is unknown.

And that would be it for the list of actual clown killers, if not for one more high-profile murder.

The kingpin's assassin

Francisco Rafael Arellano Felix was enjoying his birthday party in Baja California, Mexico, when he was gunned down by a clown wearing a pink wig and a round, red nose.

This was no ordinary victim, however.

The 64-year-old man shot dead in front of his family and friends, as well as politicians and sportsmen, had once controlled the drugs trade along the US border.

Image copyright Getty Images Image caption History shows us far more doctors kill than clowns - and no one is scared of their local GP

But at the time of his death his cartel had been severely weakened.

The clown's motive, and choice of costume, remain a mystery.

Should we be scared?

With just a handful of actual clown killers in the past century, the answer to whether or not this latest craze should have us quaking in our boots has to be no.

Between 1972 when Gacy began his killing spree and Mrs Warren's death in 1990, killings known to have been committed by clowns in the US accounted for just 0.0088% of all murders, nationally.

In fact, in the same time frame there have been at least double the number of doctors-turned-serial killers.

On top of that, arrests of clowns in the US have tended to be for minor offences only.

So on balance, you are more likely to be killed by your kindly local doctor than the slightly creepy crown waiting for you in the shadows.

Which is good news - isn't it?