NEW DELHI — The Supreme Court of India ordered several transportation restrictions in the nation’s capital on Wednesday to help curb pollution, issuing a temporary ban on the registration of some diesel cars and setting a time frame for all taxis in the region to switch to compressed natural gas.

The court halted the registration of diesel cars and sport utility vehicles with an engine capacity of 2,000 cubic centimeters or more until March 31 in the region of the capital. It also banned “transport vehicles” that are more than 10 years old from entering the capital, and ordered all taxis in the Delhi region to switch to compressed natural gas by March 1. In addition, the court doubled a tax on commercial vehicles carrying goods into Delhi to 1,400 rupees, about $20, for light-duty vehicles and two-axle trucks, and raised the tax to 2,600 rupees for larger trucks.

The World Health Organization said last year that New Delhi had the most polluted air of the nearly 1,600 cities around the world that it had surveyed. The air quality index in the city for the first week of December soared past 300 at times, according to data from the United States Embassy, which is “hazardous” by American standards — a level at which people should avoid physical activity outdoors.