Residents in Delhi and its adjoining areas saw a thick layer of smog covering the region, significantly dropping the air quality to the 'Severe' category after the Air Quality Index crossed the 400 mark and disrupted flight operations due to low visibility.
The Commission for Air Quality Management (CAQM) has called the early-morning dense smog an "episodic event".
Thick smog caused zero-metre visibility at the Indira Gandhi International Airport at 8.30 am with the Runway Visual Range varying between 125 and 500 metres at different locations, the India Meteorological Department (IMD) said.