The "killer clown" craze that recently emerged in the US is now occurring in the UK, as police forces nationwide warned would-be participants that action would be taken against them following several incidents of "clown sightings" being reported in a single day.

Thames Valley Police (TVP) recorded a total of 14 reports of people being intimidated or frightened by unknown persons dressed as clowns.

Alongside the Thames Valley area, which covers Bracknell, Milton Keynes, Abingdon and Chesham, other areas have also reported sightings throughout the UK, the Evening Standard reported.

Head of TVP's neighbourhood policy, Chief Superintendent Andy Boyd, said: "Their actions can cause fear and anxiety to other people, this could be perceived to be intimidating and threatening which could lead to public order offences and a criminal record."

He added: "In addition, their behaviour is causing multiple reports to our call takers and is tying up police resources which could impact on calls to other incidents."

A Gloucestershire police spokesman said that since Friday evening (7 October), police received six reports of clowns acting suspiciously, following people or brandishing knives, according to Sky News.

"In one case, a child was followed. Clearly this has scared people and caused real distress. We have attended these incidents as grade 1 emergencies and that limits our ability to attend to other incidents," the spokesman said.

He added: "We haven't traced anyone involved as yet as they have disappeared by the time we arrive but anyone do do find will be dealt with appropriately. Whether those involved are doing it for a joke or not, this is no laughing matter."

"These are stupid acts that are really frightening people and wasting our time. Please don't be tempted to do it. Think of the consequences."

Meanwhile, police in Scotland have also warned of action against those who take part in the craze by dressing up as clowns to deliberately scare or intimidate the public.

So far, police in Scotland have received a "few sporadic reports of individuals dressed as clowns" in various areas, although the reports did not specifically involve threats or violence.

However, Police Scotland said that anyone "seeking to cause distress and potential harm to anyone" should be aware that action would be taken.

A Facebook page titled Killer Clowns in and around Glasgow featured images appearing to show some clowns being spotted.

IBTimesUK could not independently verify whether any of these pictures or sightings are genuine, although the person who posted one of the pictures where a clown was posing under a bridge, admitted that it had been taken elsewhere.

Earlier this week, Northumbria police issued an appeal after several incidents of clowns jumping out and scaring schoolchildren in Newcastle. In Suffolk, a boy was chased by several people dressed in clown costumes on 6 October.