Kalimpong district police started a case against a film production company that orchestrated a blast without official permission in an old truck on the 80-year-old Coronation Bridge on Thursday morning at Sevoke, around 20km from here, as a part of the shooting of a web series.

Local people panicked to witness the vehicle bursting into flames with thick black smoke billowing into the sky. The sound of the blast made birds fly in fear and monkeys —there is a sizeable monkey population in and around Sevoke — jumped helterskelter on nearby trees.

“The private film company had approached the police seeking permission for the shoot on the bridge. They were, however, not given permission. But they went ahead with and surreptitiously carried out the blast. We have registered a case against them. Investigations have started,” said Aparajita Rai, the superintendent of police of Kalimpong. The blast occurred on the part of the bridge that falls under Kalimpong. The other part of the bridge falls under the ambit of Darjeeling district.

A short video, which surfaced on social media late, showed the blast on the bridge, as residents shouted at each other to arrange water and douse the flames.

“The bridge on the Teesta river connects the Dooars region with Siliguri. Initially, we thought the blast was a sabotage attempt. Later, we learnt it was a part of a film shoot,” said Suraj Thapa, who runs a food stall in Sevoke Bazaar.

Police officers from the Sevoke police outpost and Kalimpong police station rushed to the spot.

“Our officers found wreckage of the truck. On questioning the people associated with the film production company, they admitted that the blast had been carried out for the shoot. It is a serious offence as they did not have any clearance from our end,” said a police officer.

The incident has also drawn flak from social organizations, who claimed that the blast might have damaged the bridge, which is considered iconic in the hills.

The construction of the bridge started in 1937 over the Teesta and it was commissioned in 1941. It was named the Coronation Bridge to mark the coronation of King George V.

Back in 2011, after an earthquake shook the region, cracks were spotted in parts of the bridge. The state PWD carried out repairs but in due course, curbs were imposed on the movement of vehicles weighing above 10 tonnes along the bridge.

The Centre and the state have planned to come up with an alternative bridge in Sevoke Bazaar, a few kilometres downstream of the Teesta, to connect the Dooars with Siliguri and to ease the traffic load of Coronation bridge.

Chandan Roy, the founder secretary of Dooars Forum for Social Reforms, said it is their longstanding demand that the bridge be declared a heritage site and steps be taken for its conservation.

“The bridge is a key attraction for tourists. We want the police and the administration to take proper steps against the film production company for carrying out the blast in the bridge. They should also engage engineers and experts to check if the blast has caused any damage to the structure,” said Roy.

Sources in the state PWD said the bridge would be inspected in due course. “It is an old bridge and whatever be the intensity of the blast, it must have caused tremors which can affect the structure,” said a source.

(Additional reporting by Vivek Chhetri in Darjeeling)