India, Dec. 29 -- Parts of Delhi and adjoining cities of Noida, Ghaziabad, Gurugram as well as Faridabad woke up to zero-visibility fog on Monday as the air quality in the morning stood at 'severe' category with a 400-plus Air Quality Index (AQI).

Though Sunday started with AQI in the 'very poor' category, it worsened towards the end of the day as the Capital remained trapped under a combination of dense fog and high levels of pollution.

Some of the monitoring stations that recorded 400+ AQI on Monday morning include Anand Vihar (458), Ashok Vihar (430), Burari Crossing (401), Chandni Chowk (426), Jahangirpuri (439), Mundka (416), Narela (404), Okhla Phase-2 (411), according to the Central Pollution Control Board data.

As the air quali...