Policemen on electric vehicles patrol a walking street in Chengdu, Southwest China's Sichuan province, March 14, 2013. The city sent 10 patrol vehicles to the street to help with security before the 2013 Fortune Global Forum, which will take place in Chengdu from June 6 to 8. The forum is an annual conference held by Fortune magazine. [Photo/CFP]

Policemen on new electric vehicles patrol Chunxi walking street in Chengdu, March 14, 2013. [Photo/CFP]