This came even as the National Green Tribunal (NGT) rapped the city government for not taking appropriate measures to control air pollution, dubbing the situation as the worst in 17 years.

Deregistration has begun of diesel vehicles that are more than 15 years old. The decision was announced after a meeting chaired by Najeeb Jung, lieutenant-governor (LG) of Delhi. Anil Dave, the Union minister for the environment, also chaired a meeting with the environment ministers of National Capital Region (NCR) states and Punjab. It was decided that an Environment Protection Calendar would be made and followed.

The LG's office stated directions had been issued on the diesel vehicles' deregistration, to result in at least 200,000 such vehicles being taken off. A similar order had been issued in August by the NGT but had not been enforced. Delhi is the country’s sixth largest market for passenger vehicles. The number of cars registered in the city was 2.6 million as of March 2015. An estimated one in three passenger vehicles sold in Delhi runs on diesel.

On its part, Delhi Metro Rail Corporation decided to stop excavation/backfilling work for five days. Dry dismantling of concrete/brick and dry stone cutting would also be suspended. It will stop using diesel generating sets, except those required for safety and security, and carry out water sprinkling at all work sites.

Delhi Police and the various civic bodies in the city have been asked to strictly implement the action plan. The LG’s directions followed city chief minister Arvind Kejriwal's announcement of various measures to control pollution. As part of this, there will be a ban on construction/demolition activities from November 7 to 14.

Also, trucks not bound to this city and overloaded ones are not to be allowed entry. There will be a ban on crackers at other than religious functions. Polluting industries are to be shut. The meeting was attended by Kejriwal, deputy CM Manish Sisodia, other ministers and senior officials of the Centre and city, beside environmental experts.

Also, install smoke meters will be installed at all border entry points. There is to be strict enforcement, including penalisation, for burning dry leaves or garbage or tyres or rubber/plastics in the open. A roster of officers in charge shall be made and action taken for negligence in enforcement. The LG will review the situation on November 15.

Neighbouring Haryana also announced some measures, including closure of stone crushers and suspension of brick kiln operations in affected areas for five days.

The NGT bench questioned the governments' lack of timeliness in implementing preventive measures and directed it to immediately sprinkle water on the roads to control dust. It termed the Delhi situation an emergency, while also coming down heavily on the governments of Punjab, Haryana and Rajasthan on crop burning. it asked for strict action against violators.

After a meeting with the Union minister, Haryana environment minister Vipul Goel said his government had started an awareness campaign on the pollution caused due to crop burning. Data and surveys have made it clear that the state government had successfully begun this, he added. Goel said the largest amount of pollution was caused by dust particles and vehicles; crop burning was secondary.