Police are often reluctant to act against violators, given the strong religious sentiments attached to the crackers by Hindu devotees.
Critics say arguments between rival politicians heading neighbouring states – as well as between central and state-level authorities – have compounded the problem.
India’s Supreme Court last month ruled that clean air was a fundamental human right, ordering both the central government and state-level authorities to take action.
“Delhi’s toxic air is killing us softly with its smog,” the Times of India wrote in an editorial last week, as the winter pollution returned.
“It is nothing new, but what doesn’t cease to amaze, year after year, is the state’s stilted response.”
Levels of fine particulate matter – dangerous microparticles known as PM2.5 pollutants that enter the bloodstream through the lungs – surged to more than 23 times the World Health Organization recommended daily maximum.
Soon after dawn, pollutant levels topped 345 micrograms per cubic metre, according to monitoring firm IQAir, which listed air in the sprawling megacity as “hazardous”.
It listed New Delhi as worst in the world, just above smoke-choked Lahore in neighbouring Pakistan, 400 kilometres (250 miles) to the northeast.
The New Delhi government has previously sought to cut pollution by restricting vehicle traffic, including a scheme that only allowed cars with odd or even number licence plates to travel on alternate days.
Authorities have also imposed seasonal bans on construction work and on diesel-powered vehicles from entering the city.
