Northern India encountered the recurring annual pre-winter event of air emergency where the Air Quality Index (AQI) readings of main pollutant PM 2.5 breached the 400-mark of “very poor” and landed the air of Delhi, Punjab and other northern cities into the “hazardous” category.

In a repeat of what occurs every year, Delhi is engulfed by toxic smog as air quality remained in the "severe" category at the onset of winter in the national capital, media reports said.

India’s government banned non-essential construction in New Delhi, the world’s most polluted capital, and urged residents to avoid burning coal for heating, to combat worsening air quality that has disrupted flights and obscured the Taj Mahal.