Several local police forces have now issued warnings in response to the craze. Acting Chief Inspector Darren Deex of Essex Police said in a statement: "It would appear the intentions of these ‘clowns’ is to scare members of the public; however to date there have been no reports of physical threats of harm or violence being caused."

He added: “We would also like to warn people who are thinking of being actively involved in this ‘craze’ that in doing so they may commit offences under the Public Order Act 1986 and to be more considerate of the feelings of others, especially young children and the elderly."

The origins of the creepy clown craze are unknown, though some commentators have suggested it could be connected to the approach of this year's Halloween celebrations and the enduring popularity of Pennywise, the sinister clown from Stephen King's novel IT (the film of which is currently being remade).

On Twitter earlier this week, King urged Americans to "cool" the craze, pointing out that "most [clowns] are good, cheer up the kiddies, make people laugh."