Around 30 flights were delayed at the Kolkata airport as its Internet server was down since 5.15 pm on Monday, Airports Authority of India (AAI) officials said.
A fault was detected at the local area network (LAN) of the Netaji Subhas Chandra Bose International Airport since 5.15 pm hampering check-in process of the passengers, airport Director Kaushik Bhattacharjee said.
The self-service check-in kisoks are not functional and the airlines have been issuing boarding passes manually since 5.30 pm, he said.
"Till 9.30 pm, around 30 flights were delayed by an average of 20-25 minutes," Bhattacharjee said.
The AAI owns and manages more than 100 airports - including the Netaji Subhash Chandra Bose International Airport in Kolkata - across the country.