A policewoman patrols a subway station with police dog in Beijing, capital of China, on March 30, 2010. Fu Zhenghua, director of the Beijing Public Security Bureau, confirmed the security in the capital city had been increased after the double suicide bombing in Moscow's subway Monday. [Xinhua]

Passengers go through security check at a subway station in Beijing, capital of China, on March 30, 2010. Fu Zhenghua, director of the Beijing Public Security Bureau, confirmed the security in the capital city had been increased after the double suicide bombing in Moscow's subway Monday. [Xinhua]