New Delhi topped global pollution charts on Friday, partly due to revellers defying a ban on firecrackers to celebrate Diwali, the Hindu festival of lights. India's national capital battles pollution each winter as cold air traps dust,

The Supreme Court asked the Delhi government and Police Commissioner of Delhi to file affidavits about steps taken to enforce the ban on firecrackers in the national capital during Diwali.

Firecrackers are central to Diwali celebrations for millions of Indian Hindus and this year was no different even as some cities, including New Delhi, banned their use to curb some of the worst pollution levels in the world.

A thick layer of toxic smog cloaked India’s capital on Friday as smoke from firecrackers used to celebrate Diwali, the Hindu festival of lights, pushed air pollution to hazardous levels.