The first European farmer to be hit by an outbreak of bird flu has described how he was shocked to discover 400 of his flock of turkeys had dropped dead in one night. The confirmation of the first H5N1 virus at a commercial farm in the EU has thrown France's €6bn (£4.1bn) poultry industry into chaos.

Yesterday another case of bird flu was reported in Germany's Brandenburg province and Swiss authorities confirmed their first cases of bird flu but were carrying out further tests to establish if the birds had the H5N1 strain. France also reported that H5N1 had killed another 15 wild swans in the southeast.

Daniel Clair was forced to destroy his flock of 11,000 turkeys after the deaths on Thursday at his farm in the Ain region of south-east France. "I found 400 bodies and the others were already very sick," he told the newspaper Le Parisien. "It struck like lightning." A 3km (1.9-mile) protection ring - inside a 10km observation zone - has been thrown around the farm.

"It's difficult being in quarantine but we have to do it to protect everyone else," said Mr Clair. "We've had lots of support from friends and other professionals in the industry including the agriculture minister who personally called us."

The agriculture minister, Dominique Bussereau, told France 2 television that the farm was within the security perimeter set up after bird flu was found in a wild duck nearby 10 days ago. The Poultry Industry Federation said that the turkeys may have been contaminated by dried duck excrement on straw used as bedding.

Japan and Hong Kong have temporarily banned the import of poultry products from France. President Jacques Chirac urged people not to panic and insisted that chicken and eggs were safe to eat.