Five million masks are being distributed at schools in India's capital, Delhi, after pollution made the air so toxic officials were forced to declare a public health emergency.

Axar.az reports citing foreign media.

A Supreme Court-mandated panel imposed several restrictions in the city and two neighbouring states, as air quality deteriorated to "severe" levels.

Dangerous particulate levels in the air are about 20 times the WHO maximum.

The city's schools have also been closed until at least next Tuesday.

All construction has been halted for a week and fireworks have been banned. From Monday, the city will introduce a temporary scheme so that only cars with odd or even numbered licence plates can drive on given days, in a bid to cut traffic pollution.

Delhi's Chief Minister Arvind Kejriwal said the city had been turned into a "gas chamber".

The masks are being handed out to students and their parents, and Mr Kejriwal has asked people to use them as much as possible.

The levels of tiny particulate matter (known as PM2.5) that enter deep into the lungs are 533 micrograms per cubic metre in the city. The World Health Organization (WHO) recommends that the PM2.5 levels should not be more than 25 micrograms per cubic metre on average in 24 hours.