Rising pollution levels in Delhi and in neighbouring states is a matter of grave concern, Ashok Gehlot.

The Delhi government alone cannot curb the rising air pollution in the city and the Centre must take the lead, Rajasthan Chief Minister Ashok Gehlot said on Sunday.

Pollution levels in Delhi and satellite towns shot up again on Sunday morning, with the air quality bordering the ''severe-plus'' category at several places.

"Rising pollution levels in Delhi and in neighbouring states including Rajasthan is a matter of grave concern. People are suffering since long especially children and old people," Ashok Gehlot tweeted.

"It is a health emergency, which only the Delhi government cannot solve alone. Centre has to take the lead," he said.

At 11 am on Sunday, Delhi's Air Quality Index read 483.

On Friday, the city recorded the 24-hour AQI average of 484, which prompted authorities to shut schools, ban all construction activities and declare a "public health emergency".

The Friday''s highest was the worst since November 9, 2017, when it was 486.

An AQI between 0-50 is considered ''good'', 51-100 ''satisfactory'', 101-200 ''moderate'', 201-300 ''poor'', 301-400 ''very poor'' and 401-500 ''severe''. Above 500 falls in the ''severe plus'' category.