Visitors ride camels as sun rises in Dunhuang, Gansu province, July 11, 2013. Picture taken July 11, 2013. [Photo/Agencies]

Lines of cars are pictured during a rush hour traffic jam on Guomao Bridge in Beijing July 11, 2013. Eight more cities in China, the world's biggest auto market, are likely to announce policies restricting new vehicle purchases, an official at the automakers association said, as Beijing tries to control air pollution.