Most of the early morning flights for Chennai, Mumbai, Hyderabad, Jaipur and Kochi were cancelled as the general visibility dropped to below 50 metres and the runaway visibility range dipped around 100 metres.

This is much below the required minima of 150 metres for the aircrafts to take off in a poor visibility condition, airport sources said.

Barring a few International flights, no plane landed or took off since early morning. The fog began enveloping the airport area from 10 pm last night.

Fog has been affecting the flight movements here since Monday and has led to the delay of more than 500 flights and cancellation of around 75 others.

Chaos reigns at New Delhi railway station

As dense fog continued to hamper train movement, Northern Railway today cancelled 6 trains from Delhi and announced the cancellation of another 13 trains from Sunday till January 31.

The trains which will remain cancelled on Saturday are New Delhi-Agra express, Mahabodhi express, Kaifiyat express, Delhi-Sultanpur express, Delhi-Darbhanga express and Mahananda express.

The trains which will remain cancelled from tomorrow to January 31 include Rewa express, Farraka express, Katihar-Amritsar express, Bareilly-Allahabad express and Jhansi-Lucknow express.

The cancellation comes as more than 70 trains are consistently running late since the past one week due to the dense fog in several parts of north India.

A Northern Railway spokesperson said several more trains have been short terminated in view of the foggy weather conditions.

The Lucknow Shatabdi express, which was scheduled to arrive on Friday at 10 pm, is reportedly running late by over 12 hours.