Delhi and parts of north India remains engulfed in thick layer of fog with reduced visibility posing challenges for flights and trains linking the national capital with the rest of the country.

According to a NDTV report, Delhi airport has issued a dense fog alert as thousands of passengers await patiently for their flights. Fliers have been asked to stay updated about the flight details since delays are usual on foggy mornings.

As many as 168 flights have been delayed and 84 flights cancelled at the Delhi airport today, showed flight tracker website flightradar24 this morning, with an average delay of about an hour, reports ndtv.com. But the delays ran up to several hours in some cases with a passenger claiming he had to wait 13 hours for his flight to Goa.

Four flights were diverted to Jaipur and one flight to Ahmedabad between 1 am and 5 am, the official said, reports PTI.

Major airlines like IndiGo, SpiceJet and Vistara said bad weather conditions in Delhi and Calcutta may impact flights. An early morning Delhi-Calcutta flight was diverted to Hyderabad, Vistara said.

On Sunday, 10 flights were diverted and some were cancelled as the airport operations were significantly impacted due to low visibility conditions and dense fog.