Residents in India's northern states woke up to another day of poor air quality on Tuesday, as a layer of dense fog shrouded most of the region, and pollution in the capital Delhi remained severe.

Toxic smog engulfed much of northern India on Monday and pollution readings in New Delhi hit their highest of this pre-winter season.

Delhi Chief Minister Atishi on Monday said north India is facing a medical emergency due to hazardous air quality caused by stubble burning. Addressing a press conference here, Atishi said the BJP-led central government has been doing politics over the issue of pollution but has taken no step to check stubble burning in states like Haryana,