Talking to reporters at the state secretariat before leaving for New Delhi, Banerjee said, "An alert has been sounded at airports, railway stations, important public places and all vital installations across the state."
The chief minister said the suspicion was raised after the recovery of about 100 kg of explosives in the Raghunathganj area of Murshidabad district, which sparked a security alert ahead of the Independence Day.
She also claimed that a particular political party was encouraging such terrorist groups, though she refrained from naming the party.
With the seizure of the huge quantity of explosives, police had busted a terror den at Raghunathganj area last Saturday and made some arrests.
Intelligence agencies had earlier sounded an alert of a major terror attack in Kolkata and across the state on or before August 15, police sources said.
Following the IB alert, security has been beefed up in the state, while the police launched a massive search operation after the recovery, the sources said.