Those who had already bought firecrackers can still burst them.

In November last year, the court had stopped the sale of fireworks within the National Capital Region, which includes Delhi and nearby areas, following a petition flagging the alarming rise in pollution levels after Diwali.

Last month, the court temporarily suspended the ban and allowed the sale of crackers, saying a complete ban would be an “extreme step” and a “graded approach” was needed to tackle pollution.

That verdict will now only be effective from November 1. The court today said it wants to test the effect of banning firecrackers on air quality after Diwali, the festival of lights when millions across India celebrate by bursting crackers and lighting lamps.

Each year, the festival leaves the air in Delhi thick with deadly smog and suspended particles and residents complaining of breathlessness and lung difficulties.

Last Diwali, the pollution level in Delhi was said to be the worst in 10 years.

But it was after the festival that the Supreme Court, responding to a 2015 petition by three children aged between six years and 14 months, banned the sale of crackers.

“We are the most vulnerable category when it comes to air pollution, especially from suspended particles and toxins. We are foremost prone to lung disease, asthma, coughing, bronchitis, retarded development of the nervous system and cognitive impairment," the toddlers’ petition had argued, referring to the fundamental Right to Life.

This year, cracker manufacturers challenged the ban as a drastic step that would impact livelihoods. The Supreme Court then declared the ban suspended for some time, in a ruling that firecracker makers said was "well-reasoned".

But the children went to the court again asking that the ban be restored. The petition was backed by the Central Pollution Control Board.