The Kolkata Police on Tuesday said the bomb threats received by several schools in Kolkata were hoax and a case has been lodged against the sender.

Police also urged parents to remain calm, assuring them about the safety of their wards.

Several reputed schools in the city had on Sunday night received emails from an unidentified sender, claiming that there were bombs planted in classrooms.

"We want to assure you that this email is a hoax and there is no credible threat to any school. In the past, similar mails were sent to schools in cities like Bangalore and Chennai," the Kolkata Police said in a statement.

Police started an investigation after lodging a suo motu case against the sender, who used a “proxy IP address” to send the threat mails.

"We are also in touch with the schools for any help they need," the statement said.

A senior police officer said the Internet Protocol (IP) address from which the mails were sent was traced to the Netherlands.

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