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.

Delhi faced a severe environmental crisis as the AQI hit hazardous levels in multiple areas. In response, the Delhi Police enforced vehicle checks and a ban on older diesel vehicles to combat air pollution,

India's capital was left gasping this week as air pollution smog reduced visibility to near zero and raised air quality levels more than 130 times safe limits.

As air quality index levels reach alarming figures, concerns continue to grow about the impact of pollution on public health and safety.