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.

India's capital city of Delhi has virtually shut down as air pollution hit "severe plus" levels, according to Indian government officials in its pollution control authority.

India, Delhi’s air quality index (AQI) on Tuesday morning stood at 492, which is worse than Monday’s 483. Monday’s 483 AQI was the season’s worst but Tuesday has plummeted further.

Delhi ’s government imposed the most stringent set of restrictions on the movement of vehicles and people as the toxic smog enveloping the Indian capital worsened on Monday. The city’s average air quality index was 457 in the morning,

Delhi's air quality has plunged to "severe-plus," triggering GRAP IV restrictions and impacting travel. Flights and trains are experiencing delays and cancellations due to low visibility. Travellers are advised to stay updated on schedules,