Indian capital New Delhi and several other regions in northern India witnessed no respite from air pollution as the air quality continued to deteriorate and became the most hazardous Monday morning in the city ever.

The presence of particulate matter (PM) 2.5 and 10 in the city breached the worst levels beyond the designated scales of acceptable air quality and people stayed indoors for the most part of the day.

Most monuments in the city, engulfed in smog, were scarcely visible from mere hundreds of feet of distance.

Delhi government also began the odd-even scheme of vehicles on Monday where private cars will only be allowed on alternate days based on the last digit of their vehicle number, in an effort to curb pollution.

New Delhi ranks among the world’s most polluted cities with air quality usually worsening at this time of the year.

The problem is worsened as farmers in the neighbouring Punjab and Haryana states set fire to paddy stubble in their fields to prepare their grounds for the next crop.