News on Saturday that Greece and Italy had found swans with H5N1 confirmed the arrival in the EU of a virus that has killed at least 88 people in Asia and the Middle East and forced the culling of millions of birds.
Meanwhile, Nigeria was testing what could be the first humans to be infected in Africa.
A Health Ministry official in Indonesia said on Sunday two more people had died from the virus, raising to 18 the number of deaths in the country.
Further suspected outbreaks in birds were reported, with EU member Slovenia saying it had sent samples of avian influenza H5 found in a swan to Britain for further tests to see whether it was of the highly pathogenic variety.
European officials tried to reassure people, stressing there had been no human cases reported in their region.
Xavier Bertrand, the French health minister, told France Info Radio: "I think we have to keep calm."
"With the information coming from Italy, Greece and Bulgaria as well as Nigeria, we are still dealing with a bird flu, that's to say it affects birds. There has never been a case of human-to-human transmission anywhere," he said.
"There has never been a case of human-to-human transmission anywhere"
French health minister
In Italy, Francesco Storace, the health minister, told a meeting of experts he would prove there was no need for people to be concerned.
"Tomorrow, I will be visiting all the regions and all the places where the H5N1 was found precisely to show that there is no reason for worry for humans," Storace said.
Experts fear the H5N1 strain may mutate into a form that can spread among people and cause a global flu pandemic that could kill millions.
The arrival of bird flu in Italy dominated the country's front pages on Sunday, eclipsing the start of the campaign for an April general election.
The Italian Health Ministry, which urged people not to touch dead birds, said checks were being made on a swan found dead in the central Abruzzo region. If it tests positive, it will bring the number of affected regions to four and move the crisis farther north.
At present, humans can contract bird flu only through close contact with an infected animal, something that is less likely with wild birds than farmed flocks.
But that is of no comfort to Nigeria, which last week became the first African country to confirm an H5N1 outbreak.
Nigerian health officials were waiting for test results on two children feared to be the first Africans to be infected.
Bird flu has been discovered
on farms in Nigeria
Abdulsalam Nasidi, a Health Ministry official, said: "We are suspecting this might be something, but we are trying to get the real case notes."
Although only four farms in three northern Nigerian states have confirmation of H5N1, officials believe more have been hit with the virus and the problem is compounded by farmers receiving little information on how to handle the disease.
In Iraq, veterinary experts said more than 200,000 birds had been culled in northern Iraq to stem the spread of avian flu - which has killed one teenager there - but said the virus posed no serious threat to human health.