FIFA could pull Under-17 World Cup matches out of New Delhi because of concerns over air quality in the world's most polluted capital city, the tournament director said.

Hazardous smog blanketing China's north-east sparks more red alerts, with authorities advising residents in 10 cities to stay indoors.

Beijing authorities have issued a second pollution "red alert", little more than a week after its first ever such warning.

A restaurant in eastern China has been caught charging customers an "air cleaning fee" on top of their food bills.