A thick blanket of dense fog engulfed Delhi on Friday, disrupting air and rail traffic and throwing normal life out of gear.

With visibility at the Indira Gandhi International airport down to less than 50 meters, all the departures and arrivals were put on hold since about 6 am.

More than 40 trains have either been cancelled or are running late. 

Railway officials said 14 trains are delayed, one has been rescheduled and nearly 35 cancelled due to fog.