Smoke plumes were visible across the sky as revellers let off firecrackers in the evening to mark the country's biggest festival. Every year government authorities or India's Supreme Court impose bans on firecrackers - but only rarely do those bans appear to be enforced. Globally, air pollution was the worst in India's eastern city of Kolkata, while Delhi was the fifth-most polluted, according to Swiss group IQAir. Doctors say the air quality is likely to worsen on Monday as smoke from firecrackers lingers in the air, potentially causing itchy eyes and irritation in the throat. Some Hindus resent the Diwali firecracker bans, which they see as an attempt to interfere with them observing their religious festivals.

---

Persons: Health Organization's, Deepak, Dr, Ram Manohar, Gopal Rai, Neha Arora, Hugh Lawson Organizations: Health, Ram Manohar Lohia, Delhi's, Thomson Locations: DELHI, New Delhi, Kolkata, Delhi, Swiss