NEW DELHI (AFP) - India's top court ordered a temporary ban on the sale of firecrackers in New Delhi on Friday (Nov 25), after air quality reached crisis levels in the world's most polluted capital.

The order came weeks after the Supreme Court criticised the federal government for failing to do more to tackle pollution, which it described as a "public health emergency".

"(The) Supreme Court directs suspension of licences for possessing, stocking and selling firecrackers in Delhi-National Capital Region til further orders," the court said.

It also ordered the Central Pollution Control Board, a government body, to study the harmful effects of materials used in firecrackers and report back within the next three months.

Air quality in Delhi plummeted earlier this month as millions of people set off heavily polluting firecrackers to celebrate the Diwali festival, exacerbating existing problems from the burning of crop stubble in neighbouring states.

The concentration of PM2.5 - the fine particles linked to higher rates of chronic bronchitis, lung cancer and heart disease - reached "hazardous" levels in the first 10 days of November.

Local authorities announced a series of emergency measures shutting schools and banning construction and the use of diesel generators in the city.

Schools have since reopened after air quality levels improved, and some of the other measures have been rowed back.