The emails are believed to be fabricated, but schools have been advised to contact the police if they receive any of such emails.
"We understand that these types of emails can be distressing and while we take the communications extremely cautiously, we must stress there is no credible threat," the National Crime Agency said in a statement.
READ MORE: Bomb Threats Demanding Money Sent to Number of Schools Across London
We are aware of a number of threatening emails being sent to schools and are investigating alongside partners. We understand that these types of emails can be distressing and while we take the communications extremely cautiously, we must stress there is no credible threat (1/2)
— NationalCrimeAgency (@NCA_UK) 8 мая 2018 г.
The local police department stated that the emails were first sent to schools on Monday night.
Selly Park Technology College in Birmingham was evacuated as a precaution, after receiving a bomb threat.
The police are investigating the incident.