India's top court Wednesday ordered a temporary ban on large new diesel cars in New Delhi as part of a series of tough measures aimed at cleaning up the world's most polluted capital.

The Supreme Court also doubled a tax on diesel trucks entering Delhi and barred those older than 10 years altogether, as scathing public criticism mounts over the city's toxic air.

Chief Justice T.S. Thakur ordered the ban on registration of new diesel vehicles with engine capacity of two litres or more -- typical of SUVs, jeeps and other luxury cars.

Delhi would be the among the world's first cities to introduce such strict measures after Lebanon banned diesel vehicles in 2001. Paris plans similar action in future to cut diesel exhaust fumes which are considered more harmful than petrol ones.

India's courts are pushing authorities to act over Delhi's filthy air, ranked as the world's worst in a World Health Organization (WHO) survey last year of more than 1,600 cities.

Delhi's air routinely worsens in winter months as millions of poor people light fires to stay warm and cooler air and clouds trap pollutants.

Leading environmentalist Sunita Narain, who was in court, said judges also ordered city-based taxis to move from diesel to CNG (Compressed Natural Gas) by the end of March and banned the burning of rubbish.

"There cannot be anything more fundamental than the right to clean air and what the court has recognised today... (is) this is a public health emergency," Narain told reporters.

"There is now a ban on the registration of diesel vehicles above 2000cc across NCR (the National Capital Region)," she said, referring to the engine capacity.

The ban will last until March 31.

The court also barred thousands of diesel trucks which only enter the city every night en route to other parts of the country, in order to bypass toll roads around Delhi.

Car sales are soaring as incomes rise, with 1,400 extra vehicles pouring onto the city's already crowded roads every day.

More than 23 percent of the cars on Delhi roads run on diesel, which is cheaper than petrol, according to the Delhi-based Centre for Science and Environment think tank.

Shares in one of India's largest diesel carmakers, Mahindra & Mahindra, tumbled four per cent on the Mumbai exchange following the ban.

Anand Mahindra, chairman of the Mahindra Group, said on Twitter his company would honour the court's decision.

- Toxic soup -

Delhi has been enveloped in a toxic soup in recent weeks, cutting visibility and pushing PM 2.5 levels more than 10 times over the WHO's recommended safe limit.

These extremely fine particles -- less than 2.5 micrometres in diameter -- are linked to increased rates of chronic bronchitis, lung cancer and heart disease.

Facing flak over the crisis, the city government earlier this month said private vehicles would only be allowed on the roads on alternate days for a trial period in January.

In a separate ruling this week, the country's environment court slapped a ban on new registration of all diesel vehicles for nearly four weeks in New Delhi, although it was unclear if authorities were carrying out the order.

Diesel vehicles are a major cause of pollution in urban centres and calls have increased in recent years, including in London, to ban them. Paris mayor Anne Hidalgo announced earlier this year plans to bar diesel cars by 2020.

Successive governments in Delhi have faced scathing criticism for failing to come up with a strategy to tackle the smog.

The city does not issue public health warnings, unlike Beijing, which also suffers from hazardous haze levels and has declared war on its toxic air.