Czech authorities said Wednesday the H5N1 virus, which is potentially lethal to humans, had been found in a flock of chickens after its recent discovery among wild birds in Germany.
The presence of H5N1 bird flu was confirmed on a poultry farm near the village of Norin, just four kilometers (2.5 miles) from a farm where some 6,000 turkeys were slaughtered last week after the virus was detected there.
The farm in Tisova was the first incidence of H5N1 bird flu in Europe in four months.
Then on Sunday Germany joined the latest outbreak, confirming six cases in wild birds found dead near Nuremberg. That was followed by another report Tuesday involving three wild swans in the east of the country.
Zbynek Semerad, a spokesman for the Czech veterinary services, told AFP Wednesday the H5N1 virus had been confirmed by a national laboratory.
It was "the most serious animal infection" in the country since an episode of foot-and-mouth disease in 2001, he said.
Czech authorities have suggested that the virus could be due to wild birds contaminating litter.
They think the infection could have been transferred on the shoes of a worker or on a car tyre between the two poultry farms, which belong to the same cooperative.
All previous 13 cases of bird flu in the Czech Republic since March 2006 had affected wild swans only.
"There is no reason to panic. The special veterinary measures have already been widen without delay, with the aim of preventing a new outbreak of the virus," the website www.aktualne.cz quoted Czech Agriculture Minister Petr Gandalovic as saying.
"Strict controls are being followed in all the villages in the region," the veterinary services spokesman said. The area under observation had been extended from 10 to 14 kilometres, he added.
Some 28,00 chickens as well as all poultry in the village of Norin would be destroyed, Czech officials said.
Joseph Domenech, the UN Food and Agriculture Organisation's chief veterinary officer, on Wednesday praised the Czech response to the bird flu outbreak.
"Their reaction was rather good and immediate. We believe that they have the situation under control," he told reporters in Rome.
The German outbreak comes nearly a year after the last case was reported there in Dresden last August, killing a swan in the eastern city's zoo.
The only incidence of the feared virus on a farm in Germany was reported in April 2006, after which more than 21,000 poultry were killed.
Worldwide the virus has killed 191 people out of 313 infected patients, according to the latest World Health Organisation toll dated June 15.
Experts fear the death toll would multiply rapidly if the virus were to mutate and become easily transmitted between humans.