Tests for bird flu on five people taken to hospital in eastern Turkey, including a teenage boy who died, have proved negative. It was not clear what caused the death of the 14-year-old, one of four children from the same family who fell ill.Several people from the same district underwent tests in Van hospital near the Iranian border after displaying symptoms of influenza. The youngsters had all eaten chicken which had been slaughtered while showing signs of the disease. Turkey has had outbreaks of the H5N1 strain of bird flu, which has killed more than 70 people in east Asia since 2003, but has so far reported no human cases. The country lies on the path of migratory birds, which are believed to spread the virus. There have been two outbreaks of the disease in Turkish poultry in the last three months, as well as another in Romania. The people involved in the latest scare were all from the district of Dogubyazit, a remote, rural area where farming is the main way of life. Officials say poultry transport has been banned and culling will begin shortly. Millions of birds have been slaughtered across Asia and Eastern Europe in an attempt to contain the disease. It is feared the virus could mutate into a form which spreads among humans.