Nine people are under medical observation in Turkey after reports of 40 pigeons in their neighbourhood died in mysterious circumstances.
Thousands of birds have already been culled in Turkey and Romania
All nine are from Manisa, which is close to the village where the fatal H5N1 strain of bird flu was identified this week.
The nine are being monitored as "a precaution", officials said.
The news comes as EU veterinary officers begin an emergency meeting to discuss measures to contain bird flu.
The H5N1 strain of avian flu has killed more than 60 people in South East Asia since 2003.
Those who have been in the presence of dead or dying birds are most likely to become infected, and the chances of human-to-human transmission are still seen as very slim.
In Turkey, around 8,600 birds were culled this week in and around the village of Kiziksa, in the neighbouring province to Manisa.
The Anatolia news agency reported samples from the dead pigeons have been sent for testing in Izmir, western Turkey.
There have been several other reports of unexplained bird deaths in the country, but except for those in Kiziksa, none has been confirmed as bird flu.
Osman Ozturk, deputy head of the Manisa health department, said: "There is no sign of illness in the nine people."
He said they were put under medical observation simply as a precaution while their house was being disinfected.
Scientists fear that the bird flu virus could mutate into a human pandemic strain if people suffering normal human flu are also infected with the H5N1 type.
European Union Health Commissioner Markos Kyprianou confirmed on Thursday that the virus found in the Turkish village of Kiziksa was the deadly strain, adding: "There is a direct relationship with viruses found in Russia, Mongolia and China."
He went on: "It is a highly pathogenic and aggressive virus and we in the European Union have to deal with that."
The EU veterinary officers meeting in Brussels will look at measures to try to reduce the chance of contact between wild birds and poultry in high-risk areas, which could include requiring some poultry to be kept inside.
A separate EU meeting of bird flu experts is expected to issue advice on the potential risk for humans who come into contact with migratory birds.
EU foreign ministers are also to hold emergency talks on the bird flu threat on Tuesday when they meet in Luxembourg for WTO negotiations.
Turkish authorities have urged calm, amid reports of people flocking to pharmacies to buy Tamiflu, the anti-viral believed to be most effective against bird flu.
Health Minister Recep Akdag said the situation was "under control", adding that Ankara was prepared for any possible flu pandemic.
Pharmacies in Romania have also reported a big surge in demand for vaccines against common flu.
The EU moved to ban all bird and poultry products from Romania on Thursday after tests on three ducks which died last week in the Danube delta confirmed the presence of the weaker H5 strain of bird flu.
Tests for the H5N1 strain are expected to be completed on the ducks on Friday.
The EU has also banned the import of live birds and feathers from Turkey until April.
BIRD FLU OUTBREAKS IN 2005 (H5N1 STRAIN)
The H5N1 strain remained largely in South-East Asia until this summer, when Russia and Kazakhstan both reported outbreaks
Scientists fear it may be carried by migrating birds to Europe and Africa but say it is hard to prove a direct link with bird migration