A helicopter flies over flooded houses in the North Korean city of Sinuiju, along Yalu River, near the Chinese border city of Dandong, Liaoning province August 21, 2010. More than 50,000 people have so far been evacuated from a city in northeastern China after flooding from a rain-swollen river that also borders North Korea, the official Xinhua News Agency said on Saturday. Picture taken August 21, 2010.