Schools in the UK have been warned after 'malicious communications' were sent to a number 'across the country'
Devon and Cornwall Police have confimed that the communications were sent to a number of schools in the UK, sparking a major safety alert.
At least 12 schools are thought to have been impacted in Devon and Cornwall.
It has also been reported that a number of schools in Durham have also been affected by the communications.
Responding to the incident, a spokesperson for Devon and Cornwall Police told the Mirror: "We are aware of a series of malicious communications to schools in Devon and Cornwall as well as across the country.
"Enquiries continue to establish the facts and forces are working together to investigate who is responsible.
"Police take hoaxes extremely seriously. They divert police resources and cause disruption and alarm to the public."
Schools in London, Durham, Cambridge, Suffolk and the West Midlands have all been affected while many other forces have confirmed they're investigating.
A statement from Durham Police said: "We have received a number of calls from schools in our region reporting that they have been sent threatening emails.
"Police forces across the country are also believed to have reported similar incidents.
"The emails inform the school that they will be targeted in an attack later today.
"Enquiries are continuing to establish the facts and forces are working together to investigate the threat and who is responsible.
"We are requesting that parents do not ring the police as we are in contact with the schools to offer advice and reassurance, and to keep them updated on the investigation."
It is not known at this point whether any schools in Sheffield have been affected by these communications.
South Yorkshire Police have been contacted for comment.