The Japanese police are actively searching for the individual responsible for sending bomb and death threats to a large number of schools, which resulted in the schools being forced to close immediately.
Earlier this week, the threatening faxes were sent to high schools and universities in Tokyo from a number that is registered in Tokyo.
According to the authorities, no explosives have been located in any of the school buildings, and as of yet, there have been no reports of attacks on either students or faculty.
Bomb threats are extremely uncommon in Japan, which is well-known for having a low overall crime rate.
Monday marked the beginning of the first wave of messages, which were sent to schools and institutions all around the country. More than 170 schools in a single prefecture, Saitama, were sent bomb warnings, according to the government.
According to reports from the local media, one message stated that more than 330 devices had been planted, while another message read: “I planted a large bomb.”
According to some sources, the texts asked for a ransom ranging from 300,000 to 3 million yen (£1,870 to $2,320).
On Tuesday, messages were received from the same number to high schools in a variety of prefectures in and around Tokyo, including Osaka, Saitama, and Ibaraki. The messages threatened to kill students and staff with improvised weapons.
As a precautionary measure in response to the threats, many schools in Japan were closed; however, by Thursday, the majority of them had reopened.
In Japan, the use of fax machines is still rather widespread.