After a slight improvement on Monday morning, Delhi's Air Quality Index (AQI) fell to the 'very poor' category by evening because of sluggish winds, remaining at the same level on Tuesday morning, with AQI readings between 300 and 440 at most monitoring stations.

Delhi's air quality slightly improved to 'very poor' on Tuesday morning, with an AQI of 382, after experiencing 'severe' levels the previous week. Schools are instructed to operate in a hybrid mode (online and offline) for all classes until further notice,

Delhi was listed as India's most polluted city Thursday as a weeks-long air quality crisis gripping northern India has shown few signs of letting up.

Smoking a cigarette is similar to being exposed to 667 micrograms per metre cube of PM 2.5, and levels could reach more than 20 times that in Delhi, Dr Vohra said. But despite warnings from scientists about the health risks associated with poor air quality, the country has not come up with a long-term solution to drastically reduce pollution.

Amid the plummeting air quality, which dipped to the “severe-plus” category in the past few days, the Delhi government ordered half of its employees to work from home and urged the private sector to follow suit. The government also implemented curbs under Stage IV of the Graded Response Action Plan (GRAP) in the Capital to tackle the situation.

India's capital city of Delhi has virtually shut down as air pollution hit "severe plus" levels, according to Indian government officials in its pollution control authority.

Experts said even though winds were predominantly calm on Saturday, they picked up late in the evening, with similarly strong winds recorded on Sunday.