BEIJING — More Chinese cities may restrict vehicle purchases in a bid to fight air pollution and traffic congestion, state media reported.

With more than 13 million cars sold in China last year, motor vehicles and their emissions have emerged as the chief culprit for the air pollution in large cities.

Beijing, Shanghai and two other cities already curb the purchase of vehicles for private use, through lotteries and auctions of a limited number of license plates.

anhua, the deputy secretary general of the government-backed China Association of Automobile Manufacturers, was quoted Thursday as saying that eight more cities are likely to announce similar policies. The eight include the port city Tianjin, near Beijing, the metropolis Chongqing in the southwest and industrial powerhouse Shenzhen, not far from Hong Kong.

Such restrictions might cut vehicle sales by 400,000 units, or 2 percent of total domestic sales, and have a “certain impact” on the country’s economic growth, the China Daily newspaper quoted Shi as saying.

China’s increasingly informed and vocal citizens have successfully pushed the government to be more transparent about how bad the air in their cities is, but, as they get richer, their desire for cleaner air conflicts with their growing dependence on cars.

The number of vehicles in Beijing has increased to 5.18 million from 3.13 million in early 2008, Xinhua reported earlier this year. Since the beginning of last year, prospective buyers have had to enter a monthly draw to win a license plate.

Each month, 20,000 lucky winners are chosen. The number of people in the draw had reached almost 1.53 million by last month.