Millions of Indians celebrated Diwali on Monday as bright earthen oil lamps and colorful lights illuminated homes and streets across the country.

Diwali, derived from the word “Deepavali,” meaning “a row of lights,” is a Hindu festival symbolizing the victory of light over darkness.

It is typically celebrated by socializing and exchanging gifts with family and friends.

Cities and towns across India were decorated with vibrant lights, and many lit oil lamps and and set off fireworks as part of the celebrations.

Shoppers crowded markets to buy flowers, lanterns and candles.

In recent years, Diwali celebrations in New Delhi have been clouded by concerns over air pollution, as smoke-emitting firecrackers cause toxic smog that can take days to clear.

On Monday, the level of tiniest particulates surged to 347 on the air quality index in parts of the city — about 14 times the World Health Organization’s daily recommended maximum exposure — according to SAFAR, the federal government’s air quality monitoring agency.

Last week, India’s top court eased a blanket ban on firecrackers in New Delhi during Diwali, allowing limited use of “green firecrackers” that emit fewer pollutants.

Developed by federal research institutes, they are designed to cut particulate and gas emissions by about 30%.

The court said they could be used during specific hours from Saturday to Tuesday.