Kolkata/IBNS: The bomb threat emails received by several schools in Kolkata were a "hoax", said the Kolkata Police on Tuesday.

About 20 city schools have reportedly received bomb threat emails at around 12:24 am on Monday.

The emails claimed bombs were placed in classrooms of several schools. The bombs will explode in the morning hours, the email sender had claimed.

Dispelling the gripping tension, police posted on X, "It has come to our attention that an email threatening the presence of bombs has been received by some schools in the city. 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 post reads.

Police said a case has been lodged against the sender of such a prank call and a probe has been launched.

"We understand that receiving such messages can be distressing, but please remain calm and rest assured about the safety of students," the police said.