A feud between rival Minecraft gamers is the reason why 24,000 threatening emails were sent to schools and colleges in the UK, Sky News has learned.
Hundreds of schools were on alert and some evacuated their buildings, telling parents to collect their children after receiving messages containing what police described as a "bomb hoax".
Police forces around the country have said there are not believed to be any "viable threats".
Sky News has learned the emails were spoofed to look like they had been sent by a gaming network known as VeltPvP.
The malicious emails were designed to result in the domain being suspended for abuse.
VeltPvP is a Minecraft player-versus-player server – a type of server run by businesses that sell items in-game to players.
Those involved in the conflict, which centres around the Velt server operators, claimed their opponents have engaged in illegal activities to harass each other.
Sky News has been able to contact one of those responsible for sending the hoax emails.
Asked whether he regretted frightening children whose schools were evacuated, the hoaxer replied: "It is horrible, it's not the nicest thing."
He added that the reaction from schools showed failures on their part and that he understands there is a chance he will be arrested.
Humberside Police said 400 schools were affected across the country.
Detective Superintendent Tony Cockerill said: "We have spoken to all schools who have contacted us, reassured them that there is no need to evacuate and offered them security advice."
Assistant Chief Constable Vanessa Jardine of Greater Manchester Police said: "I want to reiterate that there is not believed to be any direct threat following these reports which at this stage are believed to be malicious hoax communications."
Pointing the finger at VeltPvP, the hoaxer accused the network of engaging in distributed denial of service (DDoS) attacks and targeting other rival Minecraft servers.
Abusive behaviour features in images and video purporting to be of individuals connected to VeltPvP.
"What that network has done is horrible," the hoaxer said.
But Carson Kallen, Velt LLC's chief executive, hit back telling Sky News: "That's completely false… I hope this person gets caught."
It is not the first time Velt has been targeted. Mr Kallen told Sky News he had been the victim of so many swatting attacks he now knows the officers at his local police station.
This is the first time the gamers' grievances have spilled over to affect hundreds of schools.
In a statement, VeltPvP said: "We've been being harassed by a group of cybercriminals that are trying to harass us in any way possible.
"We're extremely sorry for anyone who had to deal with this, but just know it's fake."
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Asked if he felt remorse for Monday's scares in schools, one of the attackers said: "Mentally, kind of, yes – that's human nature – but within the community, you have to become very thick skinned or you'll get exploited."
He added: "I'm not going to lose sleep over it."