The threatening letters spoke of bomb blasts at the stock exchange, state transport depot, Bank of Baroda and two Gujarati language dailies, Gujarat Samachar (news) and Sandesh (message). Police officials said it could have been an attempt to strike terror in the minds of people. "All the letters are written by one person and posted on July 31, 2008 from head post office Vadodra. Investigations are on. As the calls are concerned, we have searched the entire premises, but nothing has been found," said Rakesh Asthana, police commissioner, Vadodra.
Police squads with sniffer dogs and bomb disposal personnel combed the stock exchange for any suspicious looking objects.
Stock exchange officials said security was stepped up as a preventive measure.
"We have beefed up security on every floor. We have also tightened security at the entrance as well. We will be installing CCTV cameras in two to three days. We will collect visiting cards of everybody who will be coming to stock exchange as precautionary measure," said Sudhir Shah, chairman, Vadodara stock exchange.
Meanwhile, the BJP blamed Pakistan's Inter-Services Intelligence (ISI) agency of masterminding the bomb attacks.
"I have already number of times underlined on many occasions the direct or indirect link of the ISI in most of the terrorist attacks and blasts in India. Now, US has shown Pakistan a proof of its deepening ties with the terrorist organizations," BJP chief Rajnath Singh said in Chennai.