New Delhi/IBNS: "We should not become the most polluted city in the world," the Supreme Court was told during a hearing on the air pollution that has choked the national capital Delhi, media reports said.

Amicus curiae and senior advocate Aparajita Singh told this to a top court bench comprising Justice Abhay S Oka and Augustine George Masih.

"We are in severe mode today. They (Delhi government) have not yet taken any pre-emptive measure yet. Nothing has been done. We should not become the most polluted city in the world," advocate Singh told the top court as quoted by Bar and Bench.

The next hearing will be held on Monday.

During a hearing on the Diwali firecrackers ban violation, the Supreme Court had wailed on the authorities' failure to take measures to curb bursting of crackers.

The court had said every citizen has the right to live in a pollution-free environment. The right has been guaranteed under Article 21 of the Constitution, asserted the top court.

"Prima facie we are of the view that no religion promotes any activity which promotes pollution or compromises with health of people," the Supreme Court had said as quoted by Bar and Bench.

Delhi is engulfed by toxic smog as air quality remained in the "severe" category at the onset of winter in the national capital.

The Air Quality Index (AQI) in Delhi was 432, which falls in the 'severe' category, at 6 am on Thursday.

It has slightly improved since it was recorded 'very severe' at 452 at 11 pm on Wednesday.

Over 200 flights have been delayed owing to the poor visibility at the Indira Gandhi International Airport in New Delhi, which houses the residence of the Prime Minister.