Indian police arrested hundreds of revellers after a frenzied night of festival fireworks turned city air toxic nationwide yesterday despite a pre-emptive court ban on the smog-fuelling party.
More than 300 people were arrested in Delhi, the world's most polluted major city, where the Supreme Court had restricted public fireworks to two hours in the evening and insisted on use of cleaner "green" firecrackers to mark the Hindu festival of Diwali.
But the choking capital's 20 million residents largely ignored the court's ruling and staged a free-for-all night of colourful, deafening pyrotechnics that left the megacity's air more than five times over safe limits.
Firecrackers are traditionally let off during the Diwali week but worsening air quality at the onset of winter in Delhi and most of northern India has forced authorities to call for desperate measures, including banning use of private cars.
Major Delhi monuments including India Gate and the Red Fort were shrouded in a noxious grey haze yesterday. Commuters donned masks as visibility on major roads was reduced to barely 50 metres (yards).
Ambient air quality touched 595 yesterday morning, according to the US embassy in Delhi which independently monitors pollution levels.
Cities like London and Paris by comparison recorded 41 and 52. Any reading over 100 is considered hazardous and a danger even to healthy people.
Many Hindu hardliners, who have been emboldened since Prime Minister Narendra Modi came to power in 2014, have criticised the Supreme Court over the ban, terming it an attack on their faith.
Inhabitants of other cities such as Kolkata in the east and Mumbai in the south also flouted the restrictions, pushing up pollution levels. In Kolkata more than 200 people were arrested, police told AFP.