This city of Pakistan has earned the title of the world's most polluted city, with an Air Quality Index (AQI) of 394.

During the winter months, Delhi experiences severe pollution, driven by a combination of factors, such as low wind speeds, dropping temperatures, high moisture levels and the presence of pollution particles that act as surfaces for condensation.

A thick layer of fog was seen in Anand Vihar, Kalkaji, Nehru Place, and Akshardham Temple localities among other places in the national capital, as the city's air quality dropped to 385 at 8 am today.

Delhi's air quality is expected to deteriorate further, with the AQI likely to exceed 400 and fall into the 'severe' category on Tuesday and Wednesday, due to stubble burning in neighbouring states and unfavourable wind conditions.

The second stage of the Graded Response Action Plan has been implemented in the national capital, banning the use of coal and firewood.

Vehicular emissions top cause of air pollution, but stubble burning in neighbouring states aggravates the situation

National capital's average air quality on Monday slipped into the 'very poor' category for the first time in the season, as the residents of the city woke up to a hazy morning with smog also visible at some places.