- Delhi's air pollution at 15 times the permissible limit
- Chief Minister says "a gas chamber", court says it's public emergency
- Use helicopters to sprinkle water, combat dust: top green court
Here are the 10 latest developments in this big story:
For nearly a week, Delhi has been covered with a thick fog of smoke, with millions complaining about eyes burning and a persistent cough.
A combination of smoke from burning farm residue in surrounding states, fireworks for Diwali, dust from construction works and vehicle emissions has pushed up levels of the most dangerous particles, known as PM 2.5, to more than 15 times the safe limit.
The country's top environment court today came down hard on the governments of Delhi, Punjab, Haryana and Uttar Pradesh for contributing to the making of a public health crisis.
Lawyers for the states admitted that they had "not fully read" a series of orders by the National Green Tribunal, which has demanded the compilation of a plan to ensure better coordination and cooperation between them.
"Why did you not use helicopters to sprinkle water over Delhi and its surrounding areas," asked the tribunal, which has banned all construction and the use of brick kilns for a week.
The National Green Tribunal has also asked for a plan tomorrow on what emergency measures will be taken "when pollution levels peak again".
Delhi Chief Minister Arvind Kejriwal has declared Delhi a "gas chamber," primarily blaming crop-burning by farmers in neighbouring states like Haryana and Punjab for the smog.
Schools in Delhi have been shut down till tomorrow .
The Chief Minister has advised residents to stay indoors as much as possible and work from home.
The Delhi government has said it is considering whether to include another session of the odd-even scheme, which restricts the use of private cars to alternate days.