According to police officials, patrolling and picketing has been increased as the entire state from Kolkata to bordering districts has been put under a security blanket.
Multi-tier security has been put in place with security personnel guarding important areas and installations.
Security personnel from Kolkata police, quick response teams and the reserves have been deployed while police pickets, barricades and checks have been set up at various points in and around the metropolis.
Security has also been tightened at Metro stations, the airport and railways stations, police officials said.