Kolkata, July 30 : Kolkata has been placed on high alert after an e-mail from the terrorist group 'India Mujahideen' to a TV channel and other media houses warned of blasts at the Calcutta High Court and at a top private hospital.
As many as 70 per cent of vehicles disappeared from roads after an investigation search was launched.
Police have detained Kaushik Bose, the son of a cyber cafe owner in Kolkata's upmarket Salt Lake area, and questioned him throughout the night.
Kaushik said he would help the police identify the people who had sent the threatening e-mail from the cyber cafe.
The cafe was operating illegally, said police.
What was most mysterious about the mail was that it mentioned a car bomb and gave the registration number and type of vehicle. A search was launched for the car but it turned out to be used by Land and Land Reforms Minister Abdur Rezzak Mollah.
"I came home in the same car. It is still parked at Tiljala police station where it is normally kept for the night," Mollah said.