CHENNAI: The Cyber Crime wing of Chennai police (CCB) has taken over investigations to trace the sender of the hoax bomb threat to City schools on Thursday.

City Police Commissioner Sandeep Rai Rathore, who attended a city school as part of road safety awareness initiatives by the Traffic Police on Friday, a day after the bomb threat told media persons that they (City police) are taking all possible efforts to trace the origin of the e-mail.

"My appeal to the parents is that there is no need to panic. I am in a school now. We are investigating. I can disclose details only after we make the developments. The sender has sent threats to several schools. We (city police) have a system in place and I can assure you that the right action will be taken," Commissioner Sandeep Rai Rathore told media persons.

A senior police officer said that the user seemed to have used a VPN (Virtual private network) to send the threats, and cybercrime teams are investigating if the IP (Internet protocol) address was masked.

City Police will also be seeking the help of Interpol to trace the sender, according to officials.

On Thursday, an email threatening the possible presence of bombs received at 13 private schools in Chennai in the morning kept the police and parents on tenterhooks.

It eventually turned out to be a hoax after bomb squad personnel conducted checks at the schools in Mannady, JJ Nagar, Anna Nagar, Gopalapuram, Nandambakkam and Royapettah.

Prem Anand Sinha, Additional Commissioner of Police (South), Chennai at a press meet held on Thursday had said that the "email service" through which the threats were sent was a "problematic" one as it makes it difficult to trace the sender.