As the air quality index dropped to “severe” on Thursday, the Commission for Air Quality Management imposed restrictions across the National Capital Region to curb pollution, The Indian Express reported.

In a tweet on Thursday, Delhi Chief Minister Arvind Kejriwal announced that all primary schools schools will be closed on November 3 and November 4.

Construction activities, barring essential ones, have been banned. The transport department has said that it will impose a fine of Rs 20,000 on BS-III petrol and BS-IV diesel vehicles being used. The Delhi Metro will take 20 extra trips across its network starting from Friday, in accordance with the action plan.

The restrictions are part of Stage 3 of the Graded Response Action Plan that kicks in when air quality deteriorates. Delhi Environment Minister Gopal Rai said on Friday that Stage 4 of the plan will be implemented if the pollution levels worsen, reported The Economic Times.

Rai also called upon the central government to become more active in addressing the air quality problem, emphasising that the entire North India was breathing polluted air. “It doesn’t seem like there’s a Union Environment Ministry in Delhi,” Rai said.

The minister said that the Delhi government was taking all possible steps to address the issue. “The effect of the Delhi government’s steps is visible,” he claimed. “If we talk about pollution throughout the year, in 2015 there were only 109 days when the air quality was good. This year it has been good for more than 200 days.”

But Delhi Lieutenant GovernorVinai Kumar Saxena wrote in a post on X, formerly known as Twitter, that he will hold a meeting with Kejriwal and Rai on Friday.

“The situation arising out of air pollution in the city is extremely worrying,” wrote Rai. “I appeal to the people to remain indoors as much as possible and to not expose themselves especially children and elderly to hazardous ambient conditions.”

Air quality plunges in the winter months in Delhi, which is often ranked the world’s most polluted capital. Stubble burning in Punjab and Haryana, along with falling temperatures, low wind speed and emissions from industries and coal-fired plants contribute to air pollution in the region.

The air quality index, or AQI, dropped from 364 on Wednesday afternoon to 418 by 9 pm on Thursday. On Friday afternoon, the AQI reached over 700 in some parts of the national capital region. An air quality index ranging between 401 and 500 falls under the “severe” category. A reading of above 400 can affect healthy people and seriously impact those with existing illnesses.

Also read: How India can improve its air quality monitoring mechanisms