Hertfordshire Constabulary today warned people dressing as “killer clowns” that they face possible prosecution after a knife-wielding clown caused panic near a children's playground.

The force said it was investigating a series of incidents where people have dressed as clowns trying to scare others, as the craze continues to sweep the country.

READ MORE: 'My daughter is scared to leave the house' - knife-wielding clown spotted near children's playground.

There has been a number of reported incidents across the county since Thursday including:

• On Thursday, October 6 at around 9.51pm, a man dressed as a clown was approaching shoppers leaving Tesco in Jarman Park, Hemel Hempstead.

• On Friday, October 7 at 8.32pm, a woman reported that she was being chased by clowns in London Road, Sawbridgeworth. Officers attended immediately and there was no trace of the woman or the clowns.

• On Friday at 9.24pm it was reported that there was a man dressed as a clown in Poles Lane, Ware. Officers attended and no clown was located.

• On Friday at 11.02pm it was reported that the caller had been told there was a clown in Six Hills Way, Stevenage, at around 6pm that day.

• On Friday at 11.06pm it was reported that a teenager had been involved in a verbal altercation with a man in a clown mask in Burns Road, Royston.

• On Tuesday at 8.20 am a girl walking through an Alleyway by Roe Hill which comes out on to Woods Avenue heard a noise behind her and turned around to see a man wearing a clown mask.

• On Tuesday shortly before 7 am a boy was walking through St Nicholas’ Fields in Stevenage where he saw two people dressed as clowns scaring people.

Police said they couldn't give an exact number of call-outs.

READ MORE: Watford schools warned they will be targeted by sinister clown group.

Superintendent Richard Liversidge said: “Although the people dressing up as clowns may think they are taking part in some harmless fun, they should be mindful of the impact their actions may have on others and be aware that any behaviour that causes another person alarm or distress could lead to them being arrested.

“We want people to enjoy themselves as we approach Halloween but not at the expense of others.

“In one incident a man dressed as a clown was approaching shoppers outside Tesco in Jarman Park, Hemel Hempstead, whilst being filmed by his laughing friends.

"They may have thought this was a comical prank but it was causing distress to others.

“It is also important that people use social media responsibly and do not post items that could further fuel this inappropriate activity and create unnecessary fear within the community.”

He added: “At this stage it is unclear whether some of these reports have been made by hoax callers. I’d like to remind the public that the Constabulary will take robust action against anyone who makes hoax calls to the force as this can divert precious resources away from real emergencies.”

The "clown craze", also known as "killer clown", appears to have been inspired by clown-related pranks in the US and has seen a string of copycat incidents across the country.

Anyone who witnesses or an experiences an incident which is causing harassment, alarm or distress should call Hertfordshire Constabulary on 101.