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.

Javier Ceppi said that air quality in Delhi was a "serious concern", particularly after the Diwali festival which this year falls in October -- the month the tournament will be held.

"The match schedule is not finalised yet. One of the reasons for that is the pollution. And pollution in Delhi is a serious concern," the FIFA official told the Indian Express daily, in comments published Wednesday.

"You cannot reduce pollution from one day to the next, to the amount that would need to be reduced for hosting games," Ceppi added.

FIFA announced in 2013 that India would be the host nation for the U-17 World Cup, to be held in six cities across the country including Delhi.

Last year saw record pollution levels in Delhi around Diwali, the Hindu festival of lights, during which tens of thousands of revellers let off firecrackers.

The problem is exacerbated by the burning of crop stubble after the harvest in neighbouring agricultural areas at the same time of year.

In 2016 schools in the Indian capital were forced to shut as authorities ordered a series of emergency measures to try to ease the crisis, including a temporary ban on construction.

A 2014 World Health Organization survey of more than 1,600 cities ranked Delhi as the most polluted.