New Delhi, Nov. 9 -- A thick grey haze engulfed Delhi on Monday morning, reducing visibility and causing respiratory distress to residents as the city's Air Quality Index (AQI) dropped to 370, in the 'very poor' category.

The severe deterioration followed a night of widespread firecracker bursting during Diwali celebrations, well beyond the limited hours permitted by the Supreme Court.

According to the Swiss monitoring platform IQAir, Delhi ranked as the third-most polluted city in the world on Monday morning.

The Central Pollution Control Board (CPCB) classified the citywide average AQI as 'very poor', with numerous monitoring stations already recording 'severe' levels above 400.

The worst-affected areas included Sonia Vihar, which r...