Indian officials have banned half of all private vehicles from operating in the capital, New Delhi, because of poor air quality.
An order announced Monday creates a system based on vehicle license numbers to restrict personal car use on New Delhi's roads. Vehicles with odd number license plates are permitted to operate only on odd numbered dates, such as five, seven and nine. Those with even numbers can be driven in the city only on even dates, such as six, eight and 10.
Officials estimate the new rule will keep about 1.2 million registered vehicles off the roads each day. More than 600 police teams were deployed around the capital with the power to hand out $60 fines to drivers failing to obey the law.
Officials said the measure will remain in place until at least November 15.
The ban does not affect New Delhi's seven million motorcycles and scooters or public transportation vehicles.
The restrictions were ordered as the city government declared a public health emergency because of pollution levels.
India's Central Pollution Control Board said on Sunday the average air quality index, or AQI, for New Delhi was at 494, the highest level since November 2016, when it reached 497.
The AQI is considered good when the number is below 50, and "satisfactory" when it stays under 100. AQI levels between 301 and 500 are considered "hazardous" for all population groups.
Air pollution levels across northern India reach their highest level before winter as farmers set fire to clear their fields after the harvest.
In New Delhi, air quality is also affected by Diwali. The Hindu religious holiday is celebrated around this time of year and includes the widespread lighting of fireworks.
Information released by the World Health Organization last year showed that India had the world's 10 most polluted cities.
Delhi's chief minister Arvind Kejriwal spoke about the latest air quality in a video published on Twitter.
"There is smoke everywhere and people, including youngsters, kids, elderly are finding it difficult to breathe," he said. "Eyes are burning. Pollution is that bad."
The Indian government has blamed more than half the capital's air pollution on emissions from vehicles and industry operations. In other measures, officials ordered a temporary ban on work at building projects and schools were closed until Wednesday.
India's Supreme Court called Monday for state governments to take steps to reduce worsening air quality that it said "could not be allowed in a civilized country."
The court added, "This can't go on. People aren't safe even inside their houses and rooms."