People visit the India Gate amid smog in New Delhi on Nov. 3, 2026.

Toxic air pollution in India's capital, New Delhi, surged on Wednesday to more than 30 times the World Health Organization's recommended daily limit, data from air monitors showed.

The deterioration came three days after authorities tightened measures, including restrictions on traffic and construction, to curb smog in one of the world's most polluted capitals, with the wider metropolis home to more than 30 million people.

Pollution is expected to worsen ahead of Sunday's Diwali, the Hindu festival of lights, when firework displays add to the already poisonous air.

The Supreme Court this month allowed limited use of so-called "green" firecrackers, designed to reduce emissions, during Diwali.

But restrictions are routinely flouted, with the city reverberating with explosions.

On Wednesday, levels of PM2.5—cancer-causing microparticles small enough to enter the bloodstream—hit over 461 micrograms per cubic meter in parts of the city,…