New Delhi, Nov 23 : After getting relief for two days, Delhi's air quality deteriorated again to the 'severe' category on Saturday, with AQI crossing 400.

According to the Central Pollution Control Board (CPCB), the average air quality index (AQI) in the national capital till 700 a.m. remained at 422 points.

The AQI in Delhi-NCR's various cities also remained high. City Faridabad was 290, Gurugram was 324, Ghaziabad 357, Greater Noida 295 and Noida was 345.

In nine areas of Delhi, the AQI level remained above 300 and between 400. It was 394 in Aya Nagar, 384 in Mathura Road, 397 in IGI Airport, 390 in Dilshad Garden, 388 in ITO, 394 in Jawaharlal Nehru Stadium, 398 in Pusa, and 388 in Sri Aurobindo Marg.

In 27 areas of Delhi, the AQI level remained between 400 and above 500.

It was 452 in Alipore, 458 in Anand Vihar, 457 in Ashok Vihar, 458 in Bawana, 422 in Burari Crossing, 440 in Chandni Chowk, 420 in Dr. Karni Singh Shooting Range, 419 in DTU, 432 in Dwarka Sector 8, 463 in Jahangirpuri, 418 in Major Dhyanchand Stadium, 418 in Mandir Marg, 443 in Mundka, 406 in Najafgarh, 437 in Narela, 448 in Nehru Nagar, North Campus 419, 401 in NSIT Dwarka, 420 in Okhla System, 426 in Patparganj, 454 in Punjabi Bagh, 430 in RK Puram, The score is 450 in Rohini, 439 in Shadipur, 406 in Siri Fort, 453 in Vivek Vihar, 467 in Wazirpur.

As per the CPCB, AQI between 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor and 401-500 is severe.

On Friday, the Supreme Court said that the GRAP-4 or the fourth stage of anti-pollution measures in effect for Delhi and the National Capital Region will remain in force for the next 72 hours.

The Court said it would consider next week whether to relax certain measures, particularly concerning schools, that are currently in place in Delhi-NCR under the Graded Response Action Plan4 (GRAP 4) to combat the pollution levels in the national capital region.

/IANS