On the last of Odd-Even rule, thick smog continues to engulf the national capital, making it difficult for people to breathe.
The air pollution emergency in Delhi has aggravated with the air quality index (AQI) spiking sharply to 528 on Friday morning.
The AQI on Thursday was much lower at 470 in the 'severe plus' category. The PM 10 count was also in the severe plus category at 496 and PM 2.5 count was at 324.
With a PM 10 count of 583 and PM 2.5 count of 378, the air emergency has deteriorated sharply since Thursday. The pollution control authorities had decided to shut down schools for two days after PM 2.5 levels stayed above 300 for two days running.
Weather experts had earlier predicted severe air quality on Friday due to the influence of a western disturbance, the reason behind the dense cloud cover and a dip in wind speed.
However, wind speed is predicted to pick up on Saturday and a gradual decline in pollution is likely thereafter.
An AQI between 201 and 300 is considered 'poor', 301-400 'very poor' and 401-500 'severe'.
Levels of PM 2.5 and PM 10 levels were nearly eight times higher than the normal limits at several locations in the city.
Schools have been closed till Friday as the thick smog stiffened its choke on the national capital and its suburbs.
On Children's Day, several children wrote to PM Modi, urging him to take steps to ensure that they get clean air to breathe.
"I used to enjoy soccer earlier but now I can only enjoy it on TV. I cannot play outside because the air is too toxic to breathe in," Ishan Mahant, a student, said in his missive.
Many students posted copies of their handwritten letters on Twitter with the hashtag "BacchonKeMankiBaat".
"At this point we need a strong directive from the government of India and the governments of the states affected to control this serious condition. We do have belief in our beloved Prime Minister who will surely take strong decision on this," said another student.
The Delhi government and the administration in several NCR cities had on Wednesday ordered closure of schools following a directive of the Environment Pollution (Prevention and Control) Authority.
The Central Pollution Control Board and EPCA are likely to review the situation on Friday. The Delhi government is also expected to take a call on extending the odd-even road rationing scheme.
The Ministry of Earth Sciences' air quality monitor SAFAR said due to "stagnation and very low mixing height, flushing (of pollutants) is almost insignificant.
Scattered rainfall is expected over Punjab due to the western disturbance. It is likely to lead to very low fire count over next two days, it said.
"Also, transport-level wind direction is not favourable for intrusion. Hence, stubble contribution is estimated to reduce significantly by tomorrow to around 5 per cent," it said.
The AAP hit out at the Centre for not taking "concrete steps" to tackle the menace despite the apex court's directions in this regard.
Senior AAP leader Sanjay Singh alleged that the BJP is trying to "politicise" a sensitive issue.
(With PTI Inputs)