BUCHAREST, Romania -- Romanian authorities called for calm Saturday as they quarantined an eastern region where tests confirmed Europe's first appearance of a deadly strain of bird flu that has devastated flocks and killed dozens of people in Asia.
Poland's government, meanwhile, banned the sale of live birds at open-air markets and ordered farmers to keep poultry in closed quarters beginning Monday. It also banned pigeon races.
"We are doing this to protect the public from danger," Polish Agriculture Minister Jerzy Pilarczyk said.
On Friday, after the deadly H5N1 virus was confirmed in Turkey, on Europe's doorstep, European Union experts agreed that steps should be taken to limit contact between domestic fowl and wild birds. Experts say migrating birds have spread the disease since it appeared in Southeast Asia two years ago.
Authorities around the world fear the virus could mutate into a form that can be passed among people, leading to a flu pandemic that some say could potentially kill millions. So far, most of the 60 human deaths involving H5N1 have been linked to victims' contact with birds.
In Vietnam, U.S. Health and Human Services Secretary Mike Leavitt called for all nations to work together to quickly come up with preparedness plans.
Leavitt warned that the "chances are not good" for being able to detect when a dangerous mutation first occurs and for moving fast to contain it and prevent a pandemic.
British laboratory tests confirmed that H5N1 was the virus that killed migratory birds found dead in Romania's Danube River delta.
Romanian Agriculture Minister Gheorghe Flutur placed the Dobrogea region under quarantine, requiring all vehicles entering and leaving the area to be disinfected. Checkpoints were set up on roads into the area, and the region was banned from shipping out eggs and poultry meat.
The area includes the Danube and Black Sea counties of Tulcea and Constanta, where 1.5 million people live. The two lake-filled counties are an important stop for migratory birds from Asia.
Flutur said birds in four neighboring counties were being monitored.
"We are doing what needs to be done," he said. "There should be no panic. We are proceeding the way they proceeded in other countries."
The finding of H5N1 in Romania underscored fears that Europe is unprepared for a pandemic should the virus mutate into a form that can be passed from person to person.
"Experts take the view that an influenza pandemic is inevitable and may be imminent," the European Union's health directorate said on its Web site.
But U.N. flu coordinator David Nabarro told The Associated Press in Thailand that the spread of bird flu to Romania and Turkey "doesn't necessarily mean that we've got a greatly raised risk of human pandemic influenza." It does, however, create more opportunities for the virus to mutate into a form that is dangerous to people, he said.
EU Health Commissioner Markos Kyprianou sought to calm any public fears Saturday, saying no further measures were immediately needed following the bloc's bans on imports of poultry from Romania and Turkey.
The European Commission, the EU's administrative body, has scheduled another meeting of veterinary experts for Thursday to assess developments.
In Turkey, authorities sprayed a second round of disinfectant at the quarantined village of Kiziksa, some 80 miles from Istanbul, where the H5N1 virus was detected at a farm a week ago.
Turkish officials said the virus had been contained in Kiziksa. But Mustafa Altuntas, head of a Turkish veterinarians association, said there was a risk of new outbreaks elsewhere in the country, especially near wetlands used by migrating birds.
About 1,000 chickens were reported dead near the town of Patnos in Turkey's Agri province, but a local Agriculture Ministry official said it was not known if they were killed by bird flu or some other disease.
Test results were not expected before Monday and no quarantine was ordered, said the official, who agreed to discuss the deaths only if not quoted by name because the Turkish government rarely allows civil servants to speak to journalists.
Officials in neighboring Iran reported that 3,692 wild ducks had died in the Poldasht marshland region on its northwestern border with Azerbaijan.
But Behrouz Yasemi, an official with the State Veterinary Organization, said tests had ruled out bird flu and experts were trying to identify the "mysterious disease." He said Iran had notified WHO of the bird deaths.
Stamping out the flu outbreaks in poultry swiftly is important for human health because the further the virus is allowed to spread, the more opportunities it has to mutate into a form that passes easily between people, sparking a human flu pandemic.
In 1918, an influenza pandemic believed to have originated in birds killed more than 40 million people around the world. Subsequent pandemics in 1957 and 1968 had lower death rates but caused extreme disruption.