Delhi's air quality remained in the "very poor" category for the second consecutive day on Sunday even as authorities warned that it may further deteriorate in the next couple of days.
The overall Air Quality Index of Delhi was recorded at 301, which falls in the 'very poor' category, said the data from the Central Pollution Control Board.
On Saturday, a haze engulfed the national capital and the worst air quality of this season was recorded at AQI 324.
Anand Vihar, Mundaka, Narela, Dwarka Sector 8, Nehru Nagar and Rohini all showed 'very poor' air quality and are inching towards severe pollution levels, it said.
An AQI between 0 and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".
The Supreme Court appointed Environment Protection Control Authority on Friday held a meeting with state governments and Delhi government officials to discuss the pollution situation in the national capital.
An EPCA member on Friday said stock of the situation was taken and it was decided that special attention would be given to vulnerable hotspots where 'poor' or 'very poor' air quality is observed.
The PM2.5 (presence of particles in air with a diameter of less than 2.5 micrometres) touched a new high at 167. The PM 2.5, also called "fine particulates", can be a matter of more serious health concern than PM10.
The PM10 level (presence of particles in the air with a diameter of less than 10 micrometres) in Delhi stood at 293, according to the data from the Centre-run System of Air Quality Forecasting and Research (SAFAR).
A CPCB official said a number of factors were responsible for the deteriorating air quality, including vehicular pollution, construction activities and meteorological factors like direction of wind which is now flowing from the stubble burning areas.