EU officials have approved plans by France and the Netherlands to vaccinate millions of poultry against bird flu.
Some EU members had opposed plans for vaccination
The programme, initially opposed by several countries, will be limited to birds in specific high-risk regions.
It came as health officials in Austria said two chickens had the deadly H5N1 bird flu virus - the first time it has appeared among poultry in the EU.
The health ministry said the chickens had been kept with an infected swan and commercial flocks were not affected.
The chicken and three ducks came into contact with the wild swan at an animal sanctuary in the southern city of Graz, officials said.
The swan had been taken there earlier this month from an area affected by the virus, in breach of regulations imposed after the first H5N1 case was recorded in wild birds in Austria.
Seven EU countries have now confirmed cases of H5N1 in wild birds.
Hungary, the latest EU member to confirm the H5N1 virus, said on Tuesday that tests showed the virus in three dead swans found last week.
Croatia also confirmed the H5N1 strain on Tuesday in a swan found dead on Ciovo island, just off the coastal city of Split. Slovakia is testing suspected cases in two wild birds.
In other developments:
- Officials in India's Maharashtra state begin sealing off the town of Navapur where bird flu has been discovered
- The UN's food agency warns that the spread of bird flu in Nigeria could spell disaster for the region and urges the government to implement a nationwide vaccination programme
- Indonesian officials say they suspect a 27-year-old woman from Jakarta has died from the H5N1 strain, making her the country's 20th bird flu victim if the diagnosis is confirmed by tests.
In Brussels, EU vets and health experts agreed to allow France and the Netherlands to carry out preventative vaccination on millions of birds against the H5N1 strain.
The programmes were authorised only for specific birds in specific regions, the panel said, and would be "subject to rigorous surveillance and control requirements".
The move towards vaccination had been spearheaded by the Netherlands and France, the EU's two largest poultry producers.
Under the plans agreed, vaccination will be allowed in the Netherlands for free-range poultry, those most in danger of contact with wild birds, as an alternative to keeping them indoors.
France will be allowed to vaccinate ducks and geese in three areas in the west and south-west thought to be at high risk, among them the coastal Landes region.
Germany, Austria, Denmark and Portugal had all opposed vaccination in earlier talks.
EU Health Commissioner Markos Kyprianou argued that recent outbreaks of bird flu "compounded the need to explore every possible option" to fight its spread.
"Targeted preventative vaccination, accompanied by sufficient guarantees, is allowed," he said.
EU ministers are also discussing the economic impact on the poultry industry and the issue of compensation for farmers.
Poultry sales have plunged in Italy, Greece and France since the confirmation of H5N1 outbreaks.
The lethal H5N1 strain has killed more than 90 people, mostly in Asia, since late 2003. It can be caught by humans who handle infected birds, but is not yet known to have passed from one person to another.
Scientists have warned that if the virus mutates, it could create a pandemic that could kill millions of people.