Policemen and armed police prepare to patrol in Kunming, the capital city of Southwest China's Yunnan province, August 3, 2011. More than 1,000 policemen, armed policemen and security guards were mobilized to carry out a 24-hour patrol mission around the city's main bus stops, train stations and highly populated areas in what the deputy director of the city's police bureau, Zhang Yuming, said is an effort "to ensure social stability and to thwart any kinds of criminal activities". [Photo/CFP]

Armored vehicles are used by armed police to patrol in Kunming, the capital city of Southwest China's Yunnan province, August 3, 2011. [Photo/CFP]