A woman who had tested positive for the bird flu virus was released from a hospital in central Turkey Saturday, the Anadolu news agency reported, according to DPA. Gulsen Yesiltirmak was hospitalised in the town of Sivas after being diagnosed with the deadly H5N1 strain of the virus. She is the fourth person in Turkey to have been successfully treated and released. Eleven others who have tested positive to the virus are still being treated at hospitals around the country. None of the 11 are considered to be in a life-threatening condition. Three children aged 15, 14 and 11 from the eastern Turkish town of Dogubeyazit have died after contracting the virus from reportedly playing with the heads of dead chickens. Meanwhile agriculture ministry workers continued to cull poultry in various provinces across the country where there have been confirmed and suspected cases of the virus. Agriculture Minister Recep Akdag on Friday said more than 450,000 birds had been killed in the last two weeks.