Updated

After discovering cases of bird flu in wild ducks, Austria ordered farms within a 1 kilometer (0.6 mile) radius on the affected shoreline of Lake Constance, which also borders Switzerland and Germany, to keep all poultry indoors.

The creation of a "protection zone" to keep wild migrating birds from transmitting bird flu to farm poultry will be implemented on Thursday in coordination with Switzerland and Germany, a Health Ministry spokesman said.

The measure also requires poultry farmers and owners of pet birds to have a veterinarian check their animals at least once a month.

Authorities have discovered a highly pathogenic strand of the H5N8 bird flu in the corpses of five wild ducks in the area this week, although they said there was no evidence the virus could be transmitted to humans.

They are investigating a case of suspected bird flu in a domesticated bird in Vorarlberg province and expect final results on Friday.

If the tests are positive, authorities would have to cull all birds in the affected farm and establish a 3 kilometer protection zone and 10 kilometer surveillance zone around the site, the spokesman said.

The Dutch government said on Wednesday it had ordered farmers in the Netherlands to keep poultry flocks indoors after wildfowl infected with bird flu were discovered in several European countries.

Hungary's food safety authority said last week it had found traces of bird flu at a poultry farm in eastern Hungary and would destroy 9,000 turkeys to protect nearby populations.

(Reporting By Shadia Nasralla; Editing by Hugh Lawson)