Security has been beefed up again around the American Center, on Jawaharlal Nehru Road, on Wednesday after guards at the entrance spotted “suspicious movement” by three unidentified persons near the building in the morning.

Police personnel and commandos combed the vicinity on reports of “shadowy figures” lurking behind the shrubbery opposite the Center, but the intensive search yielded nothing offensive. The deputy commissioner of police (south), along with two assistant commissioners, later rushed to the spot.

“We decided to clear the thicket opposite the Center and tighten security arrangements immediately after inspecting the site,” said Shivaji Ghosh, deputy commissioner of police (headquarters). “No suspicious object was found in the bushes. Still, we will illuminate the spot to provide the guards with a clearer view of the area across the road,” said an official.

Apart from the commandos and reserve forces, plainclothes policemen, armed with 9-mm pistols, have been deployed for round-the-clock surveillance of the building.

“These measures are being taken in view of the recent security threats. An alert has been sounded and we don’t want to take any chances. The situation is a lot different from last year, and we have to be on our toes,” said Ghosh.

Narrating the morning’s incident, a police officer said security forces positioned behind sandbag bunkers saw three shadowy figures. “They took up position and two of the guards crossed the road silently in a bid to get near the bushes. Others were instructed to open fire if they spotted anyone escaping,” added the officer.

The two policemen went close to the bushes, but found nothing except two empty mineral-water bottles.

“We have no idea from where the bottles were brought,” said Ghosh.

A message was sent to the Lalbazar headquarters immediately and the control room rang up the deputy commissioner of police (south) Kuldip Singh, leaving a message for him.

Singh and other officials rushed to the spot and inspected the site for over an hour. After the inspection, it was decided to clear the shrubs and clean up the zone.

Morning-walkers, too, panicked when they saw such a large number of police personnel in front of the American Center building. Many inquired whether there had been a fresh terrorist attack on the imposing structure. The police officials assured the crowd that nothing untoward had happened.