Security was intensified at Calcutta airport (top), Howrah station (middle) and Birla Mandir on Thursday following the serial blasts in Assam. Pictures by Bishwarup Dutta and Sanat Kumar Sinha

The serial blasts that rocked Guwahati on Thursday morning sent ripples through Calcutta, 1,081km away.

Brothers Chakrabarti when into battle mode at Writers’ Buildings and Lalbazar as an alert was declared.

Home secretary Asok Mohan Chakrabarti said at Writers’: “The state has been put on high alert in order to pre-empt any such incident. The police have been asked to keep a special watch at markets, railway stations and all crowded places.

“We appeal to the general public to inform the police if they come across any abandoned bag or vehicle on the roads. The need of the hour is to be very cautious.”

At Lalbazar, his brother Gautam Mohan Chakrabarti went into a huddle with top cops to review the security cover at the airport, railway stations and other vital installations in the city.

Following the police commissioner’s orders, more than 15 special cars fitted with anti-sabotage equipment scoured parking lots around town.

“Around 7,000 cops had been deployed for Kali puja immersion but on Thursday that was scaled up to 10,000,” said Vineet Goyel, the deputy commissioner of police, headquarters.

From afternoon, small teams of officers hit the streets to check over 100 points picked on the basis of inputs provided by the special branch of the city police. These included temples, like Kalighat and Birla Mandir, and Kali puja pandals awaiting immersion or evening soirees.

All vehicles entering the airport were being checked by security personnel. Central Industrial Security Force (CISF) personnel were deployed at strategic points and a rapid reaction team was put on alert. “The number of plainclothesmen has been increased. Sweeping squad personnel are scanning the terminal buildings for unclaimed objects,” said an airport official.

All entry points at Howrah station boasted full body scanners and armed police personnel with handheld metal detectors. But what Metro saw between 4.15pm and 4.45pm was hardly reassuring. Hundreds of people walked in unchecked as the body scanners kept beeping hysterically.

There was some security bustle on platform number 9, for the Howrah-Rajdhani Express, but policemen elsewhere were seen sitting around, yawning, sipping on tea or watching television.

“I don’t know where and how you saw lapses. We have done everything necessary in the wake of the blasts in Assam. Everyone suspicious is being stopped and checked,” argued platform inspector Pradip Kumar Biswas.

Sealdah was less of a security sieve despite one unmanned full body scanner at one of the gates. At 5pm, two sniffer dogs were seen checking heavy luggage and armed policemen scanning almost every entrant. “There are 40 armed policemen at the main gate to check those entering the station,” said P.K. Basu, the deputy superintendent of police, GRP.

Markets are the other soft targets. At City Centre, the parking lots were filled with private security personnel and policemen causing a long car queue at the gate..

“Explosives fitted to cars, bikes or cycles have been used in most serial blasts. So parking lots are top priority,” said Dulal Bose, a security in-charge at the Salt Lake mall.

Most shoppers didn’t seem to mind. “This is necessary for our safety. But this should be done every day, not for a few days after a blast,” said Dipankar Ghosh, 57, a bank employee waiting too drive in.