BEIJING, Sept. 21 (Xinhua) -- China will construct 150 kilometers of urban rail tracks annually in the next ten years, according to the Ministry of Construction.

Ten cities, including Beijing and Shanghai, already have 22 operating urban rail lines of 602 km, while 36 lines of more than 800 km are under construction in 13 cities.

In the late 1990s, China had only 110 km of urban rail lines in operation, said the ministry.

Meanwhile, more than 60 urban rail lines of 1,700 km have been approved by the State Council for 15 cities and more than ten other cities are planning their own lines, according to the ministry.

Urban railways have become a key transport sector as China's 1.3 billion people become increasingly urbanized and subway trains are always over-loaded at peak times.

By 2010, when Shanghai hosts the World Expo, the city will have11 rapid transit lines that will be able to carry six million passengers, or 35 percent of all commuters, each day.

Beijing's planning agencies said that the city would have nine commuter rail lines stretching 200 km by 2008, and 19 lines totaling 561.5 km by 2020.