The annual Diwali celebrations in Delhi have caused huge amounts of air pollution.
Thousands of sparklers and fireworks were set off to celebrate the Hindu festival but the smoke caused heavy smog.
The result of this is that air pollution is now around 30 times higher than the World Health Organisation’s recommended level.
Delhi is home to 16 million people and is the 11th most polluted city in the world.
WHAT IS DIWALI?
Diwali, the Hindu festival of lights, is the most popular of all the festivals from South Asia.
It is also the occasion for celebrations by Jains and Sikhs as well as Hindus.
The word Diwali comes from the Sanskrit word deepavali, meaning “rows of lighted lamps”. Houses, shops and public places are decorated with small oil lamps called diyas.
People also enjoy fireworks and sweets too, so it’s really popular with children.
The festival is usually some time between October and November. It changes each year.
This year, it will fall on Sunday, October 30.