Hundreds of Italian schools were evacuated after receiving hoax bomb threats. ( Reuters: Francesco Fotia )
Schools in Italy, Scotland, Northern Ireland and Ireland have received bomb threats.
It is the latest wave of hoax alerts to hit Europe.
The warnings caused schools in Italy to be evacuated, disrupting the day of parents and pupils.
Schools across Italy have been evacuated after around 6,300 of them received bomb warnings, the latest in a series of threats and cyber attacks around Europe against supermarkets, blood banks, air traffic and broadcasters.
Scotland, Northern Ireland and the Republic of Ireland also said many of their schools received a similar email threat from abroad, but it was classed as a hoax and did not disrupt classes.
In Italy, schools closed swiftly after the warnings, prompting many parents to drop what they were doing to collect children.
"My daughter Dafne started crying because the kids did not understand what was happening, and she was still shaken when I picked her up," said Nensi Bego, parent of a child at the Mazzini middle school in Rome.
"This is so annoying. It's obvious it's just a hoax that disrupts lessons and disrupts everyone's day."
The evacuations sent many pupils out onto the streets, requiring parents to leave work or abandon plans to pick them up. ( Reuters: Francesco Fotia )
A copy of the message seen by Reuters also included a threat to target Prime Minister Giorgia Meloni. Ms Meloni said the bomb alerts posed no danger and that police and other public bodies were monitoring the situation.
"All students have been taken to a safe area and remain under the supervision of teaching staff," one school in Rome informed parents through a messaging app.
The email received in Italy was signed "Mikhail Andropov, leader of the Vilayat of Misoginistan," according to a copy of the message seen by Reuters.
"The [school] emails are public. [Sending the bomb alert messages] was as easy as drinking a glass of water," a national security source told Reuters.
The same purported author claimed responsibility for email bomb threats sent on Friday to newsrooms in Ireland and Bulgaria .
Dozens of flights were last week diverted or searched after hoax threats were received by airlines. ( AP: Gregorio Borgia )
Some European officials suspect Russia may be behind a campaign of disruption to everyday life in European nations supporting Ukraine after Moscow's invasion.
Russia denies that and accuses the West of a smear campaign.
Iran is another suspect. France summoned Iran's ambassador on Tuesday after accusing Tehran of a cyberattack that disabled refrigerators in hundreds of supermarkets last week.
Iran rejected those accusations as "baseless and hostile".
Italian Defence Minister Guido Crosetto said Wednesday's threats were part of a clear strategy "to spread fear and create anxiety," according to Adnkronos news agency.
"It is not always the work of foreign countries or hostile entities. There are also attention-seekers and lunatics who, at a time like this, cannot wait to unleash terror in a city or a region," he added.
Antonello Giannelli, head of the Italian School Principals Association, said the alerts were upsetting for students, families and school staff.
"Even though today's threats are clearly hoaxes, we cannot underestimate the consequences of incidents that alarm entire school communities and disrupt the normal conduct of educational activities," he said.
