Thick fog in Delhi has caused significant disruption to flight operations at the citys international airport. In an advisory issued today, Delhi airport requested passengers to confirm flight schedules with airlines before travelling.Due to dense fog, flight operations at Delhi Airport may be affected. Passengers are requested to contact the airline concerned for updated flight information, the airport authority stated.Any inconvenience caused is deeply regretted, they added.Kind attention to all flyers!#Fog #FogAlert #DelhiAirport pic.twitter.com/2gvYr8FSTR— Delhi Airport (@DelhiAirport) January 14, 2024The fog follows days of cold, polluted air in Delhi and across northern India. Yesterday, low visibility forced IndiGo to cancel or delay many flights. In a statement, the airline apologised for the inconvenience: Our staff kept passengers apprised of all delays and cancellations across airports and made every possible effort to facilitate the passengers. We sincerely regret the inconvenience caused to our passengers.This morning, visibility dropped below 200 metres in some areas as temperatures plunged to 4C. The thick fog enveloping Connaught Place and India Gate emphasised the capitals notoriously poor winter air quality. Pollution control agencies have reimposed restrictions under Stage III of the Graded Response Action Plan (GRAP) across the National Capital Region. The Delhi transport department has banned construction work and restricted certain vehicle traffic.The cold snap has prompted measures to protect vulnerable groups. Many homeless people took shelter in government-run night shelters to escape the freezing conditions.Kind attention to all flyers!#Fog #FogAlert #DelhiAirport pic.twitter.com/AzfbWo89wJ— Delhi Airport (@DelhiAirport) January 15, 2024Meanwhile, the Delhi Education Department has delayed school opening times until 9am due to the weather. Classes cannot run beyond 5 p.m. either. Last week, the department closed nursery and primary schools in anticipation of the foggy conditions.The Indian Meteorological Department has issued cold alerts in parts of northern India, including Uttar Pradesh, Punjab and Haryana. More fog and freezing temperatures are forecast over the coming days.