Delhi Environment Minister Gopal Rai on Tuesday called for forming a regional implementation committee to control pollution in National Capital Region states, PTI reported.

He made the statement at a virtual meeting of environment ministers of states from the region. The meeting, chaired by Union Environment Minister Bhupender Yadav, was aimed at reviewing air quality management and measures to reduce air pollution in the region.

The National Capital Region encompasses the city of Delhi, as well as several districts surrounding it in Haryana, Uttar Pradesh and Rajasthan.

At the meeting, Rai said, citing a report, that over two-thirds of Delhi’s pollution emanates from sources outside the city.

“According to a [Centre for Science and Environment] report last year, only 31% of Delhi’s pollution is due to internal sources, while external sources contribute 69%,” he said. “The NCR states will have to take all necessary steps to reduce air pollution.”

The minister also called for imposing a complete ban on firecrackers in National Capital Region states, as done by Delhi, according to PTI. In September, Delhi had banned banned production, sale and use of firecrackers till January 1, 2023.

“We have to understand that the problem of pollution is not related to any particular state,” he said. “The states have their own limits but there is no limit to pollution, so a regional implementation committee should be formed for the NCR states, which can continuously monitor pollution.”

Air pollution in Delhi generally worsens with the onset of winter due to colder temperatures, construction dust, traffic, industrial emissions and stubble burning in nearby regions, among other factors.

In September last year, Rai had sought creating a joint action plan that could be enforced in Delhi and neighbouring states to control air pollution in winter, according to India Today.