As the number of cars in the upcoming southern city of Shenzhen has touched the one million mark, the city's mayor has urged its residents to stop the purchase of new cars.

With 90,000 new cars registered already this year, Xu Zongheng fears that more cars in the city will give rise to the traffic problems. The English-language China Daily quotes Zongheng as saying, "Problems arising from the city's traffic are mounting. I hope residents take this into consideration when planning to buy cars."

AFP reports that the annual growth rate of cars in the city is estimated at 18.6 percent, thus out pacing road construction and leading to ever-increasing traffic. Also, more cars means the city will also face major problems of air-pollution caused by exhaust fumes.

Apart from Shenzhen, Beijing is also facing similar problem. The city authorities are now planning to take one million of the city's three million cars off the road for a two-week trial period in August to reduce air pollution.