 -- The city of Delhi, India, is surrounded by a thickening blanket of smog that covers the city, making the sky less visible and the air less breathable.

The Indian Medical Association (IMA) declared a public health emergency in the city on Tuesday -- the city's air quality rating is above the highest levels on the index. People have been advised to avoid any outdoors activity and to keep children indoors to avoid the risks of the “severely harmful” air quality.

The Education Minister confirmed elementary schools will be closed on Wednesday, saying an extension of the order is possible. Delhi Chief Minister Arvind Kejriwal published statements on Twitter today, including a request to Sh. Manish Sisodia, Deputy Chief Minister, to consider closing schools for a few days.

The problem is expected to linger for some time.

The Doctors Association’s requested that Kejriwal cancel the Airtel Delhi Half Marathon, according to local media reports, which is about two weeks from now, on November 19.

Flight schedules have also been changed due to low visibility today; more than 20 flights have been delayed and at least four have been rerouted.

The Air Quality Index (AQI) in Delhi is currently 316, which is above the threshold for “severely polluted” and has health implications, according to officials. The AQI scores range from excellent and good at 0- 50 and 51-100, lightly polluted and moderately polluted at 101-150 and 151-200 and heavily and severely polluted are 201-300 and 300-plus.

The air quality in the Punjab region is even worse than Delhi; the index is 462. Many believe stubble burning -- setting fire to leftover straw after grain harvests -- in the province has contributed to the extreme pollution there and elsewhere.

Despite restrictions on stubble burning in Punjab, many do not comply with the new regulations and the smoke is creating problems not only for that region, but also for adjacent provinces in both India and Pakistan.

Imran Hussain, who is in the Delhi cabinet as minister of food and civil supplies, environment, forests and election, said he has asked Punjab officials to curb burning of agricultural residue to control air pollution in Delhi. But no action has been taken.

Punjab officials deny the effect on Delhi's air quality, saying stubble burning has been reduced by thirty percent since Punjab banned crop burning in 2013.