Police Scotland said threatening messages were sent widely to distribution lists, but nothing suggested they posed a credible threat or any danger to the public.

The hoax threats, which originated from outside of the UK, caused dozens of schools to evacuate their students and staff, according to reports.

Police Service Northern Ireland (PSNI) said more than 300 schools in Northern Ireland had reported a “concerning email” to police.

In a statement, the force said police were conducting urgent enquiries and liaising with the schools that were targeted.

Assistant Chief Constable Anthony McNally said: “We take incidents of this nature very seriously and we understand the concern in the community, school communities and for students and parents.”

“We urge everyone, in the meantime, to be vigilant and report anything suspicious to police immediately by calling 101, or 999 in an emergency.”

Police Scotland added: “We understand how distressing messages of this nature can be for pupils, parents, carers and school staff, and the concern they can understandably cause.

“Our advice is that there is no requirement to evacuate schools or keep children away from education based solely on the content of the emails.

“Police Scotland’s Cyber and Fraud Unit is carrying out extensive enquiries to establish the source of the messages, and officers continue to liaise with law enforcement partners across the UK and internationally.”

A number of schools in Northern Ireland and Scotland also closed following a hoax bomb threat last month. Stormont’s education minister Paul Givan said on that occasion the threat was “Islamist” and had been signed off “Allahu Akbar”.

Alliance Party MLA Paula Bradshaw hit out at “the reckless bomb threats”, while the Education Authority condemned the messages for causing fear and distress among pupils, parents and staff.

The EA said: “The message has similarities with a bogus threat sent last month, which was declared a hoax by PSNI. EA is liaising with police on this latest message.

“At this stage, we have not been made aware of any evidence of any credible threat to schools.”

The hoax bomb threats also come as at least ​300 schools in Italy were evacuated after receiving bomb alert messages on Wednesday.

It is unclear if the threats are linked, but they follow a string of bomb threats across Europe in recent weeks, which have targeted supermarkets, air traffic, broadcasters, and blood banks.

John McGhee, the executive director of education at Glasgow City Council, said: “You may be aware of media reports this morning about a threatening email about a device in schools that has been sent to schools across the country - our police colleagues have confirmed this is a hoax and that schools should not be evacuated.

“Police officers will investigate the source of these emails. We will continue to work closely with our police colleagues as part of the investigation.”

He added: “We know that these incidents will cause anxiety and I want to reassure you the safety of our children, young people and staff is our top priority, and we will always follow the correct procedures in this type of situation.”

Highland Council said: “Emergency protocols were activated in Highland schools this morning, as we awaited further guidance from police.

“Schools will be in touch with parents directly regarding arrangements following any precautionary measures taken this morning.”