Air pollution in the north of India has “reached unbearable levels,” the capital Delhi’s Chief Minister Arvind Kejriwal says.
In many areas of Delhi air quality deteriorated into the “hazardous” category, with the potential to cause respiratory illnesses.
Low visibility caused more than 30 flights to be diverted on Sunday.
Rules have now gone into effect allowing only cars with odd or even number plates to drive on given days.
The initiative is aimed at getting more vehicles off the road in an effort to curb air pollution.