Children are being asked to perform 'inappropriate acts' and being targeted and groomed by online predators through popular online game Fortnite, a school has claimed.
The warning has been issued by a school after five of its students were contacted by a person via the online video game.
Kaye Haywood, headteacher of Beacon Ace Academy in Bodmin, Cornwall, said the children were told that 'scary things' would happen if they didn't comply.
Fortnite is a free online multiplayer shooter video game, first released in 2017, which has risen in popularity- with fans including England and Spurs stars Dele Alli and Harry Kane.
Ms Haywood added that five local children had been groomed but many more had been targeted by the online predator.
In a letter to parents, she wrote: 'We have been contacted by another school in Bodmin regarding five of their pupils being groomed via the game 'Fortnite'.
'This person has made contact with many children and has been grooming five that the school know about.
'This has been traumatic for these children as they have been encouraged to perform inappropriate acts and they have been told frightening things will happen to members of their families if they do not cooperate.
'The police have been informed and are currently investigating these cases.
'They have found that this person has contacted these children via their other social media accounts, for example Instagram, as they have shared their details.
'He has also directed children to his YouTube videos.'
The letter continued: 'Please, please, please be aware of what games and other media your children are accessing and ensure you and your children are aware of exactly who they are communicating with.
'This issue was raised by a parent to the school and intervention has been put in place before anything more traumatic happened.
'This could, however, have had a much more sinister outcome.'
The popular game has lured in a number of celebrities and sports stars, according to their social media accounts.
The highest profile ones are the likes of Antoine Griezmann and Dele Alli, who have both performed the 'Floss Dance' celebration after scoring goals this year.
Drake joined Ninja for a record breaking stream of Fortnite, and has played with him on more than one occasion.
Los Angeles Lakers player Josh Hart is a huge fan of the game, and even wore custom Fortnite basketball shoes on court.
WHAT IS FORTNITE?
Fortnite is a game that originally launched as a disk back in July 2017 and was then turned into a free-to-download game by its developer, Epic Games, in September.
There are three forms of the game: 'Battle Royale', 'Save The World' and 'Playground'.
Save the world is the original form of the game and is currently not available to play as part of the free-to-download game, instead it comes as part of a £30 ($40) extra.
It is a co-op mode with a story that's playable solo or online with friends.
Users compete in teams of up to three to complete a variety of missions.
It is rumoured that the game will be added to the free-to-play version of the game in the future.
Whilst Save The World may be the original version of the game, its sister mode is by far the most popular.
Battle Royale is a game of survival where players create a superhero avatar and compete against each other on a dystopian island.
Each game, or 'match' as each competition is known, starts with 100 players.
The aim of the game is to be the last one standing. Users can form allegiances and play in small groups.
To enable this and the interactive experience, the game allows completely open communication between players.
Inspired by the Hunger Games novels and films, gamers search for weapons to help them survive.
Armed with quirky weapons and amusing dances, the game has swept across the gaming world, with children flocking to it.
While there is no exact figure on how many children play Fortnite, the game has so far pulled in an audience of over 125 million players.
Playground is the latest addition to the game and is a consequence free mode with more loot and unlimited respawning to allow players to get creative.
It involved groups of up to four people working as a team and the players can hone their skills as the practise in advance of entering Battle Royale where they will face better players.