Whatever the causes of the smog, by one ranking Delhi was not just the most polluted city in the world, but “nearly five times as bad as the second most polluted city, Dhaka,” in Bangladesh next door, as Shashi Tharoor, a leader of the opposition in Parliament and best-selling author, posted on X.

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.

New Delhi was the most polluted city in the world for the second consecutive day on Tuesday, wrapped in a dense and toxic smog – mixture of fog and pollution – raising air pollution to levels over 60 times considered safe by the World Health Organization (WHO).