France is investigating a possible case of bird flu in a woman who has returned from Turkey, the French health ministry said on Sunday. The woman was hospitalized in Montpellier following a two-week stay in Turkey in a region that "in principle" has not been affected by the disease, he said.

This case was being treated as potential bird flu because of the "symptoms and because the woman saw dead birds while traveling in a country affected by the epidemic," the ministry said in a statement. She showed symptoms of flu and breathing difficulties and has been placed in an isolation ward, where she is receiving antiviral treatment, the ministry said.

Bird flu has hit 26 Turkish provinces. At least four people have died from the deadly H5N1 strain of the disease. The epicenter of Turkey's outbreak is in the east, near to Syria, Iraq, Iran and Armenia.

The H5N1 bird flu virus has killed at least 80 people since late 2003. Victims contract the virus through close contact with sick birds, but there are fears it could mutate into a form that can pass easily from person to person, sparking a pandemic.