At least nine fishermen are missing after their boat capsized into the Bay of Bengal during a sudden tornado early on Saturday.

Fellow fishermen, who were in nearby boats, feared that the missing men might have been trapped in the trawler as most of them were asleep when the tornado struck, causing the boat to capsize amid the swirling winds and rough seas.

The incident occurred around 2am on Saturday, some 60km from Bagher Char Island. Eight of the 19 fishermen on board were rescued by nearby fishing boats. All the fishermen are residents of Kakdwip.

Despite an extensive search later in the day, the remaining nine fishermen were not found. However, fishermen in nearby boats located the capsized vessel. Attempts are on to bring it to shore to Namkhana, 40km away, so that the motor room and spaces used by fishermen to rest may be checked.

Bijan Maiti, general secretary of the West Bengal United Fishermen’s Association, expressed deep concern over the incident.

“Our members, who are close to the site, are working to bring the boat ashore. We are waiting anxiously to inspect the boat’s interior, especially the motor room, to confirm if any of the missing fishermen are trapped inside,” Maiti said.

The eight rescued fishermen, brought to Kakdwip for treatment, reported that they jumped off the boat just before it capsized.

“We tried to alert others but they could not hear us as they were sleeping,” one of the rescued fishermen said. All eight survivors were admitted to Kakdwip Subdivisional Hospital but five were later discharged after first aid.

The boat, MV Baba Govinda, which set out for deep-sea fishing from Kakdwip on Wednesday, encountered the tornado late Friday night.

According to local sources in Kakdwip, at least five nearby fishing boats were working to bring the capsized vessel to the shore.

“Once the boat reaches the shore, we will pump out the water to check if any of the missing men are trapped inside,” a fisherman said.

Bringing the boat ashore is proving to be a difficult task.

Assistant director of fishing (marine) at Diamond Harbour, Surajit Bag, told The Telegraph: “Fishermen tried to tow the boat using chains, but they struggled to secure it properly underwater. We have requested assistance from the disaster management team and the Indian Coast Guard to involve their divers in the effort.”

“It is still partially submerged,” Maiti told reporters. “Our primary aim is to bring it ashore and see if any of the missing fishermen are trapped inside.”