|A man in protective clothes holds a dead water bird found at the border of a dam in Kelbra, central Germany, July 4, 2007|
Tests on three swans found dead in northeast France have confirmed the presence of the H5N1 strain of bird flu, which can be fatal to humans, the agriculture ministry said Thursday.
Agriculture Minister Michel Barnier said the threat level from bird flu would be raised from "moderate" to "high" following the results of the tests.
"The national laboratory of the French agency for animal health has confirmed the presence of the H5N1 highly pathogenic virus on the three swans found dead in a pond near the town of Assenoncourt," said a ministry statement.
France had stepped up surveillance after several cases of the H5N1 virus were discovered in Germany and the Czech Republic last month.
Authorities had sealed off the pond in the Moselle department where the birds were found last week.
In accordance with EU norms, a one kilometre (0.6 mile) exclusion zone has been established around the Assenoncourt pond, as well as a wider 15 kilometre "observation" zone.
France's only outbreak of H5N1 was early last year, when it was detected in 62 dead wild birds, contaminating a turkey farm in central France.
A restricted area around a dam in Kelbra, central Germany, was set up after bird flu was discovered in dead wild birds in the region of Thuringia and Saxony-Anhalt.