India, Nov. 3 -- A thick haze shrouded Delhi's skyline on Tuesday morning, as the national capital's air quality remained in the "very poor" category, just days ahead of Diwali.

Delhi's air quality index (AQI) stood at 331 at 7:05 am on Tuesday. The 24-hour average AQI on Monday was 324, the worst in 271 days, up 63 points from Sunday's 261. It was 60 on Friday, when the air quality was "satisfactory".

Data from 58 of the 59 monitoring stations showed that eight were in the severe category on Tuesday morning, including Bawana, Narela and Punjabi Bagh. Only one station, IGNOU in Maidangarhi, was in the moderate category.

On Tuesday morning, CPCB listed PM2.5 as the main pollutant at 53 of Delhi's 58 reporting stations and PM10 at five. ...