A scary prank is causing panic and fright among people living in towns and cities across Italy and Spain.
The chilling "Samara Challenge" involves pranksters dressing up in a white sheet with their hair hanging over their face and slowly wandering the streets in the dead of night as if they are haunted.
They are mimicking the female lead character in the American horror series of films "The Ring".
Rome, Naples, Sardinia, Barcelona and Sicily have all been targeted resulting in calls for vigilante groups to try and stop the "menace".
There have been numerous sightings in Rome where the craze is currently at its peak, both in isolated areas and tourist hotspots such as monasteries, parks and churches.
Police were inundated with calls on just one night alone.
In the town of Manfredonia, police had to be called in after three separate "Samara" figures were spotted in a local cemetery and one even climbed to the roof of a chapel.
While in Cilento in southern Italy, a sighting took on an even more chilling twist when a woman tried to take a picture of a "Samara" who then pulled out a knife.
The woman ran off but nearly got hit by a passing car.
Residents who have seen the challengers walking the streets say it is a very scary sight which is causing some people a great shock.
They are worried that someone might die from heart failure or one of the girls dressed only in a white sheet could be attacked if in an isolated place.
The "Samara" is encouraged to walk some distance away from a friend who records their antics and there is concern that they would not get to her in time if attacked.
There has already been one incident when a girl was harassed and pushed by a group of teenagers.
Numerous pictures and videos are being posted on the social network to gain as much impact as possible.
Shocked witnesses are calling for internet groups to be set up so sightings can be reported and the police immediately called in to stop them. Some residents are also organising their own watch patrols.
"This is a joke in bad taste which is spreading into all of our suburbs," said one.
Organised patrols have been organised in Sicily where a 30-year-old woman was arrested for spreading alarm.
Police are warning challengers of the dangers involved and possible repercussions if people in the vicinity "don't share the same sense of humour".
