US space agency National Aeronautics and Space Administration (NASA) has released multiple pictures of crop residue burning in Punjab and Haryana from October 21 to October 29. NASA's satellite images show a dramatic increase in stubble burning in Delhi's neighboring states-Punjab and Haryana in last eight days.

The rise in stubble burning and burning of firecrackers during Diwali have deteriorated air quality in Delhi.

The Air Quality of Delhi has slipped to "severe" category post-Diwali. On Thursday, the overall AQI stood at 471 in the national capital, according to the Ministry of Earth Sciences' air quality monitor, SAFAR.

Twenty-two of the 37 air quality monitoring stations across Delhi recorded air quality in severe category on Thursday morning.

According to SAFAR, the share of stubble burning in Delhi's pollution rose to 35 per cent on Wednesday, the season's highest.

Weather experts said the pollution in the city aggravated due to an unfavourable wind speed.

Meanwhile, Arvind Kejriwal-led Aam Admi Party government has identified five "critically polluted" areas after examining pollution data and asked the municipal corporation to intensify actions at these locations.

The "critically polluted" areas are Wazirpur, Anand Vihar, Ashok Vihar, Vivek Vihar and Bawana.

Further, the Delhi government will also distribute 50 lakh N95 masks among school students, said CM Kejriwal.

Kejriwal, on Thursday, directed all schools in Delhi to suspend outdoor activities. Delhi Deputy Chief Minister Manish Sisodia said the decision to shut schools would be taken "when the need arises".

In November 2017, the government had shut schools for a few days due to poor air quality.

(With PTI inputs)

Also read: Pollution levels spike in Delhi-NCR post Diwali

Also read: Delhi's post-Diwali air quality better than last year but worse than 2017