The politics over pollution also intensified, as Ministers from neighbouring states quality skipped a crucial meeting called by Union Ministry, with the Delhi government claiming the latter to be "not serious".

Pollution is set to worsen until at least November 4, with high moisture trapping the pollutants and calm wind not allowing them to disperse, according to the System of Air Quality and Weather Forecasting And Research (SAFAR).

The stubble burning in Punjab and Haryana has about 30 per cent impact on Delhi's air quality, say experts from Central Pollution Control Board (CPSB).

The Air Quality Index (AQI) on Thursday was 393 in Delhi, considered "very poor" or near "severe". Ghaziabad in Uttar Pradesh saw a slight improvement with an AQI of 377.

Haryana's Gurugram had an AQI of 427, while Faridabad and Noida had 407, making them the three most polluted cities in the country on Thursday.

The government has imposed a ban on construction activities, coal and biowaste-based industries, and brick kilns across NCR till November 10.

The Supreme Court appointed EPCA said that it is considering imposing more restrictions including a ban on truck entry in Delhi, if the air quality falls further.

"300 water sprinklers are being used across Delhi to tap down the particle pollutants," said Delhi Environment Minister Imran Hussain.

However, the politics and verbal spat intensified as Ministers from Haryana, Punjab, Uttar Pradesh and Rajasthan skipped a crucial meeting on air pollution held here by Union Environment Ministry.

Delhi Chief Minister Arvind Kejriwal, his deputy Manish Sisodia, and Delhi Minister Hussain blamed the Centre for the absence of Ministers from these states.

"Why didn't ministers from other states attend? It's a collective problem and I urge everyone to please work together. Only then can we find a solution," tweeted Arvind Kejriwal.

Delhi Environment Minister Imran Hussain, who attended the meeting, said the meeting should have been taken seriously.

Union Environment Minister Harsh Vardhan said that concerned ministers are in touch.

"Let there be no politics on this matter. We have talked to the Ministers from Punjab and Haryana and they sent their representatives here," Harsh Vardhan told reporters here.

He said that the stubble burning had reduced by 30 per cent over last year, which was good but not enough.

Harsh Vardhan and Imran Hussain also flagged off five buses fitted with air-filters at the top to tap particle pollutant, under a pilot project to ply 30 such buses.

The ministers also launched an Asthma manual for schools to help schools build better management plans for emergencies and recognise symptoms among children, especially in cities like Delhi with at least four to five months of poor air quality every year.

On Thursday, business venture Blueair collaborated with East Delhi Municipal Corporation to distribute 5,000 N-95 mask among the municipal workers.

Delhi on Thursday saw a rise in particle pollutants with average dispersion of PM2.5 and PM10, or particles with diameter less than 2.5mm and 10mm, being 241 and 437 microgrammer per cubic meters -- about 4 times the permissible limit.

Chandni Chowk, Dwarka sub-city, Rohini, R.K. Puram, Narela and Punjabi Bagh were among the 18 regions out of 36 which reeled under 'severe" air quality with PM2.5 above 400 units.

The permissible limit for PM2.5 and PM10 is 60 and 80 units by national standards and 25 and 50 units by international standards.

Meanwhile, SAFAR advised people to avoid all outdoor physical activities and those with asthma to keep relief medication handy.