The national capital was on high alert Wednesday after over 150 schools in Delhi-NCR got an identical message on their official IDs around 4 am — an email “threatening to blow up” the premises. The incident triggered mass evacuations of schools and panic among parents, even as Delhi Police officers and Bomb Disposal Squad (BDS) teams rushed to the spots. After a thorough check, it was declared a hoax.

Police officers said the email was sent to all schools in one go. Following a preliminary probe by the Delhi Police Special Cell’s Counter-Intelligence Unit (CIU), the email was traced to a Russian IP address — mail.ru — and the role of an organised entity is being probed, said a senior officer.

The officer added, “A VPN was used to send the email to the schools; the perpetrator possibly hacked into the database of all schools that got the hoax email. This is being investigated.”

An official said central agencies are “coordinating and sharing” information from Delhi as well as Noida police. “The National Investigation Agency is also looking at all the emails.”

The official also said similar emails were received in other states in the last two days: “Emails were sent to airports and terminals across the country. On Monday, they were sent to hospitals in Delhi.”