LUCKNOW, Dec. 20 -- Poor visibility due to fog led to the cancellation of several flights and caused delays at the Chaudhary Charan Singh International Airport (CCSIA) on Friday. Passengers were forced to wait for hours at the airport, while onward travel plans of several of them were disrupted. The Delhi route was the worst hit. Air India flight AI-2499 (Lucknow-Delhi) and IndiGo flight 6E-2107 (Lucknow-Delhi) were cancelled due to bad weather. The sudden cancellations left passengers struggling at airline counters for alternative bookings and refunds, causing inconvenience. International operations were not spared either, with flights connecting Lucknow with Dubai, Sharjah, Dammam and Riyadh landing much later than their scheduled arrivals. Passengers complained that the lack of timely and clear information regarding flight status added to their difficulties....