Kolkata/ Jaipur, Jan 04 (ANI): Security has been beefed up at the Netaji Subhash Chandra Bose International Airport in Kolkata city of West Bengal following a threat to an Air India flight. The booking office of Air India, in Kolkata, received an anonymous threat call on Saturday that an Air India flight will be hijacked. However, the exact details of the flight which is likely to be targeted are not known. It has also not been ascertained yet whether or not the call was a hoax. Reacting to the hijack threat, Aviation Expert Harshvardhan asserted on the need to take even the smallest threat very seriously. A passenger Manju Jaana said that she arrived early at the airport in view of the increased security at the airport and was ready to cooperate with the officials. Another passenger Sudhanshu Mukherjee said that it was reassuring to see so much security in place at the airport.