A man throws a hen into a cage at a wholesale poultry market in Ha Vy village, outside Hanoi April 5, 2013. Chinese authorities slaughtered over 20,000 birds at a poultry market in Shanghai on Friday as the death toll from a new strain of bird flu mounted to six, spreading concern overseas and sparking a sell-off in airline shares in Europe and Hong Kong. Vietnam banned imports of Chinese poultry. REUTERS/Kham (VIETNAM - Tags: HEALTH ANIMALS DISASTER)