Footage from a CCTV camera installed outside a private residence near the Cafe Coffee Day outlet in AD Block that was looted at gunpoint on Monday morning shows four men entering the place a little before 10.20am, police said on Tuesday.

A member of the gang had held a gun to the head of Suvankar Ghosh, who works as a barista-cum-waiter, while the other three tied him up and cleaned out the cash till containing around Rs 15,000.

Suvankar was apparently the only person in the 40-seater cafe when the gang walked in.

Investigators did not get any footage of that time from three other houses in the locality because of a power outage when the robbery took place. The fourth house had power back-up.

“Footage from a camera pointing away from the entrance to the cafe shows four men, all of them clad in jeans, walking briskly towards it,” an officer in the Bidhannagar police commissionerate said.

According to him, Suvankar’s description of the robbers matches that of the men seen in the CCTV footage.

Amit Javalgi, the deputy commissioner of police (headquarters), said none of the four faces resembles any criminal known to be active in Salt Lake and its nearby areas. “This seems to be the handiwork of a new gang,” he said.

All police stations under the jurisdiction of the commissionerate have been alerted and the detective department is investigating the case.

“Cameras installed inside the cafe have no footage of the period 10.10am-11.30am. We are trying to find out whether this is just a coincidence,” an officer said.

A meeting had been convened recently at the headquarters of Bidhannagar police to discuss the sudden spurt in crime in Salt Lake and Dum Dum Park.

The cafe that was looted reopened around 12.30pm on Tuesday after the authorities of the coffee chain received a go-ahead from the police.

The general manager (east) of Cafe Coffee Day, Praveen Kumar Sinha, said that additional CCTV cameras would be installed inside the cafe.

Suvankar, who hails from Bongaon, has gone on leave. “He told us that he was in shock. A blue shirt that one of the gang members had used to gag him was left behind. We have handed the shirt to the police,” the manager of the cafe said.