Bird flu has been found in swans and at two small poultry farms in the southeast of the Czech Republic, Agriculture Minister Marian Jurecka says.
State Veterinary Administration chief Zbynek Semerad said the highly contagious H5 type has been confirmed and further tests were performed to determine whether the N8 sub-type is present, which is "assumed".
A three and a 10-kilometre zones have been put in place around the infected premises in Ivancice and Moravsky Krumlov, Semerad said.
"There are farms (in the 10-km zone) with around 150,000 poultry ... these will be checked regularly," he said, adding infected birds and poultry will be culled.
It is Czech Republic's first case of bird flu in roughly 10 years, Jurecka said.
The H5N8 strain has been detected recently in neighbouring Germany and Slovakia and in other European countries.