Supreme Court has given New Delhi three days to come up with a plan to clean up the air in a city ranked by the World Health Organisation (WHO) as the most polluted in the world.
Successive local governments in Delhi have failed to check pollution from industry and increasing traffic. This is not the first time the court has passed such an order - successive local governments have failed to build roads to ease congestion.
About 52,000 commercial vehicles, excluding taxis, enter the landlocked city each day, more than double government estimates, the Centre for Science and Environment (CSE) said in a report this week. Such vehicles account for about a third of the city's pollution.
"If we are able to have a strategy to address this commercial traffic, it will help clean up the air," said Anumita Roychowdhury, an executive director at the CSE.
Hearing a plea filed by lawyer Harish Salve, the Supreme Court on Monday asked the federal government, Delhi's local government and its municipal body to come up with a solution within three days.
Delhi court banned all vehicles older than 15 years from New Delhi earlier this year in a bid to clean up the air, but the order has since been delayed.
The WHO last year said New Delhi had the worst air quality of 1,600 cities surveyed worldwide.