Three swans found dead in eastern France may have been killed by the deadly H5N1 bird flu virus, the French Agriculture Ministry said yesterday.

"The first results show a suspicion of bird flu. These tests are in the process of being confirmed at the reference laboratory of the French food safety agency AFSSA to determine whether it was the highly pathogenic H5N1 strain," the ministry said in a statement.

It had already put protection measures in place in the surrounding area and the results of the tests were expected tomorrow, it said.

France, Europe's biggest poultry producer, had increased its precautions against bird flu in June, saying the risk of the disease hitting the country had gone up after it was found in a number of wild birds in Germany.

The disease was also found in the Czech Republic last month. Last year, some 13 European Union member states had confirmed cases of bird flu - Germany, Austria, Denmark, Italy, Greece, Britain, the Czech Republic, Poland, Slovakia, Slovenia, Sweden, France and Hungary.

In France the virus was found in more than 60 wild birds and at a farm with 11,000 turkeys. It had not been detected in the country since April 2006.

More than 30 countries have reported outbreaks in the past year, in most cases involving wild birds such as swans.

Globally, the H5N1 virus has killed nearly 200 people out of over 300 known cases, according to the World Health Organisation. None of the victims were from Europe.