Kolkata, Dec 29 (IANS): A World War-II vintage 1,000-pound bomb has been retrieved during the dredging operations at the Netaji Subhas Dock of the Kolkata Port Trust (KoPT), an official said on Saturday.

"A World War-II vintage 1,000-pound bomb was retrieved while deepening the Netaji Subhas Dock berth of Kolkata Port by grab dredger on Friday. It is an aerial bomb probably from 2nd World War," a KoPT official told IANS.

An FIR has been made with the police by the port official.

"Kolkata Police is coordinating. Indian Navy and Indian Army have been informed. The bomb has been cordoned off on berth II of the dock by CISF," the port official said.

"It remained under water for many years. It is difficult to say how it landed there. Maybe, it was being carried in a ship and fell in the river while being taken to shore from ship. We do not know the exact reasons," said Commodore Suprobho K. De, Naval Officer-in-Charge, West Bengal.

"Our examination suggested that the aerial bomb was probably made in the US as there are US markings on it. We are extending our cooperation to KoPT for arranging inspections by experts. We do not take any chances with such explosives," he told IANS.

The Indian Ordinance Factory Board may also be contacted for an inspection, said the official.

Once the aerial bomb is declared safe, it can be stored in the museum, he added.