An alert was sounded across city police stations following the deadly blast in Delhi on Monday evening.

In the city, vehicles were being checked randomly, and in many cases, the passengers were being asked to step out.

Metro saw the checks on Bentinck Street, Ganesh Chandra Avenue, Central Avenue, Chowringhee, and several other places.

Security checks have been intensified at Calcutta airport and railway stations.

At Metro stations, RPF personnel were seen instructing passengers with a bag to pass it through the scanner. Usually, as closing time nears, passengers are often seen walking past the scanners without putting the bags inside.

At several stations, RPF jawans were seen walking up and down the platforms. “In the context of the present scenario, we have already alerted our security personnel,” a Metro spokesperson said.

A senior officer said all police stations had been instructed to intensify patrols, conduct naka checks, increase police presence in sensitive areas and carry out verification of guests in guest houses and hotels as part of the security drill.

On Monday night, police stations began checking the registers of hotels and guest houses, as well as the identification cards of the guests.

“We have been asked to verify if anyone suspicious is lodged in any of the hotels,” said an officer of the New Market police station.

A top city police officer told Metro: “We are keeping a strict eye on the sensitive pockets. We are trying to ensure that even the smallest of suspicious movements are detected and addressed.”