Schools warn parents about "Momo" challenge videos appearing in children's games
Schools are warning parents an online suicide game may be making its way into children's YouTube videos such as Peppa Pig.
A number of institutions across the country have posted alerts on their social media pages, telling parents of the "highly inappropriate'' videos.
According to the Parentzone website, the Momo Challenge is played over WhatsApp, with the Momo character asking would-be participants to contact "her'' and carry out a series of challenges - the final one being suicide.
The Momo character features a disfigured face with stretched features attached to a bird's body.
YouTube said it had not received any evidence of the challenge on its site.
Tracey Heap, from Ayrshire, said her 8-year-old had been left traumatised by it.
She said: "He's really scared, he's actually losing sleep because he's frightened he'll dream about it, and what can happen if he doesn't do these challenges.
"When I first saw it I was actually quite scared.
"There was this picture in front of me with these bulging eyes and it was really quite scary, so I can only imagine what a child would think."
National Online Safety tweeted: "Today we've heard from hundreds of concerned schools and parents about the horrifying #Momo challenge which has reportedly been appearing in children's YouTube videos, causing panic and upset amongst young people.''
It followed this with advice and guidance for parents including in setting parental controls, and reporting and blocking any offending material.
The school warnings come after a statement from the Police Service of Northern Ireland.
Detective Sergeant Elaine McCormill from PSNI's Public Protection Branch, said: "Whilst no official reports have been made to police, we are aware of the so-called Momo challenge and are already liaising with other UK police services to try to identify the extent of the problem and to look for opportunities to deal with this issue.
"This extremely disturbing challenge conceals itself within other harmless looking games or videos played by children and when downloaded, it asks the user to communicate with 'Momo' via popular messaging applications such as WhatsApp.
"It is at this point that children are threatened that they will be cursed or their family will be hurt if they do not self-harm.
"I am disgusted that a so-called game is targeting our young children and I would encourage parents to know what your children are looking at and who they are talking to.''
A YouTube spokeswoman said: "Contrary to press reports, we have not received any evidence of videos showing or promoting the Momo challenge on YouTube.
"Content of this kind would be in violation of our policies and removed immediately.''
No links or videos that violate the online giant's guidelines or promote the Momo challenge have been flagged with YouTube.