New Delhi: Several schools and colleges in Delhi received bomb threats over three consecutive days, prompting the police to work around the clock to assess the credibility of the emails and trace their origin. However, officials reported that the threats were sent through encrypted networks, making it difficult to identify the senders.

According to officials, the senders are using Virtual Private Networks (VPNs) and the dark web, a hidden part of the Internet not indexed by standard search engines and accessible only through specialised browsers. This anonymity allows various illegal activities, including cybercrime, human trafficking, and the trade of drugs and weapons, to flourish. VPN adds a layer of anonymity by allowing users to create a secure connection to another network.

"Tracking someone on the dark web is like chasing a shadow in a room full of mirrors. The moment you think you have found a lead, it vanishes behind another layer of anonymity," a Delhi Police officer explained.

Nine schools in the city have received ten bomb threat emails in the past three days.

Amid rising concerns over repeated bomb threats, the Directorate of Education (DoE) released a detailed 115-point Standard Operating Procedure (SOP) in May to guide schools on how to respond to such situations. According to sources, the recent threat emails followed a consistent pattern: vague yet alarming language, sent before school hours, and often routed through international servers. Police suspect that the sender or group responsible is skilled in using anonymising tools and advanced cyber tactics to evade detection.

"It is not easy to trace emails that are routed through multiple proxy servers. They are using VPN chains and tools on the dark web to bounce their location across several countries. In such cases, even service providers are often helpless," a source said.

A cyber expert of the Delhi Police said the investigating officers are no longer treating the threats as a mere prank.

"Multiple probe agencies are involved in investigating the matter. These threats are affecting children, parents and the school staff psychologically," the expert said on the condition of anonymity.

During a press conference, a senior Delhi Police officer said that the use of VPN by the sender of the emails significantly hampered efforts to track the threat.

"We were tracking the emails, but VPN makes it difficult to track their origin. We also had to check for any possible terror link," he had said.

The recurring threats have caused considerable anxiety among parents and teachers.

At St Thomas School in Dwarka, which received two threats in less than 24 hours, Rakesh Arora, the father of a 12-year-old student, said, "Schools receiving bomb threats is very worrying. It not only creates fear but also disrupts the children's studies.

"These may turn out to be hoaxes, but as parents, we can't help but be scared," he said.

On Tuesday, Varun Kumar, whose daughter is a kindergarten student, said, "This is not the first time. These kinds of threats are happening quite often. Police must take strict action against those responsible for sending such emails. It creates unnecessary panic and disturbs everyone."

"Parents are genuinely scared to send their children to school now," Kumar added.

Following the DoE's SOP, schools have tightened their security protocols, increased bag checks, restricted outsider entry, and are coordinating with the local police stations on a daily basis.

Police said that they are not ruling out any angle in their probe into the threats.

"The January case had revealed a possible link to a civil society group and a political entity, which had drawn significant attention. The accused student's father was reportedly associated with an NGO that had previously supported terrorist Afzal Guru," a senior police officer said.

Police have urged people not to panic over such threats and to report any suspicious activity. They have issued advisories and hold interactive sessions in schools from time to time, informing stakeholders how to handle threat emails and maintain evidence that could help in tracking the perpetrators. PTI