New Delhi chokes in smog after firework ban flouted

India’s capital New Delhi was wreathed in poisonous smog Friday, with air pollution worsening after a fireworks ban was widely flouted for raucous celebrations for the Hindu festival of lights, Diwali.

New Delhi’s traffic-clogged streets are home to more than 30 million people, and the city is regularly ranked as one of the most polluted urban areas on the planet.

The city is blanketed in cancer-causing acrid smog each year, primarily blamed on stubble burning by farmers in neighbouring...