#BBCtrending: French police warn about scary clowns

French police have arrested several young people behaving violently dressed as clowns, amid concerns that a disturbing subculture of "scary clowns" is spreading on social media.

Social networks have been awash with chatter about "evil clowns" after a number of recent incidents in France. The subject is among the top trending topics on the social platform Reddit. On Saturday, police in Agde arrested 14 teenagers who were dressed as clowns wielding pistols, knives and baseballs bats. In Montpellier, a man in a clown costume was arrested after beating another man with an iron bar. And in Bethune, in the north of France, a 19-year-old was sentenced to a suspended jail term for threatening passers-by while dressed as a clown.

Why are people dressing as clowns and behaving this way? Police in France believe the internet has played a pivotal role. "Since mid-October, there's been a rumour inspired by videos shared on the internet, which is worrying people about the presence of threatening and aggressive clowns in France" said a police statement.

In fact, the use of frightening clown imagery online is an international trend. Earlier this month in the US, there were several reports of scary clowns in California, Florida and New Mexico. Photos of clowns were shared on social media accounts using the name "Wasco Clown".

The Wasco Clown was was originally an art project featuring photos of an anonymous clown in the town of the same name. It inspired copycats, with some sharing disturbing images of clowns in intimidating scenarios. Social media accounts using the Wasco Clown name built up a following on Twitter and Instagram. There was also on a tribute Facebook page. There is no confirmation that these accounts are connected to incidents reported to police, and some are no longer accessible online.

Countless videos of scary pranks involving clowns are also being shared on YouTube - one of which has been viewed over 29 million times. This video shows a staged but violent attack by a clown in front of unsuspecting passers-by.

Social media is also being used as part of a counter movement. In France, police say groups are organising online to track down the clowns and they're taking the matter very seriously. "Anyone, aggressive clowns or clown hunters, found in possession of a weapon in a public place will be arrested and can be held in police custody," said a police statement. They've urged the public to stop spreading rumours online and have issued information on how to send an alert about an aggressive clown.

Reporting by Anne-Marie Tomchak. .