Primary schools in India’s capital city will remain closed until Nov 10 due to high pollution levels, a Delhi government minister said in a post on social media platform X, formerly known as Twitter.

“As pollution levels continue to remain high, primary schools in Delhi will stay closed till 10th November,” said Delhi Education Minister Atishi Marlena.

For Grade 6-12, schools are being given the option of shifting to online classes, she added.

New Delhi stands on top of a real-time list of the world’s most polluted cities compiled by Swiss group IQAir.

The city’s air quality index (AQI) on Sunday was 471, putting it in the “hazardous” category. It was followed by Lahore in Pakistan at a “very unhealthy” of 261.

The toxic air on Saturday had forced Sri Lanka to cancel their training session. The team was practising for a World Cup clash on Monday against Bangladesh in the heavily-polluted Indian capital.

An AQI of 0-50 is considered good, while levels 400-500 impacts healthy people and is dangerous to those with existing diseases.