China's Xinjiang region has culled more than 55,000 chickens and other poultry following an outbreak of a highly virulent bird flu that has infected 16,000 birds, the Ministry of Agriculture said in Beijing today. The H5N6 strain of the virus was confirmed in Yining, a city of 500,000 people, and has killed 10,716 birds, the ministry said. It is the fourth flu outbreak among poultry since October. <br/><br/>Flocks are particularly vulnerable to avian flu during the winter months and sporadic outbreaks are relatively common. The culling comes amid fears about the spread of avian flu across Asia, with South Korea battling its worst-ever outbreak and Japan and India also killing flocks. At least seven people in China have been infected this winter with the H7N9 bird flu strain and two have died.