Flights to and fro from the NSC Bose International Airport in Kolkata continued to be affected for the second day on Tuesday due to thick fog. No flights took off from Kolkata since midnight due to poor visibility, airport sources said. An Allianz Air flight, CD 7705, on the Kolkata-Silchar route, which took off at 5.40 am with 30 passengers on board, was diverted to Bhubaneswar.