The diseases likely spread to three new countries follows the recent deaths of humans from the H5N1 strain of bird flu in Turkey and Iraq, Irans neighbors, and the march of the disease into European countries Greece and Italy.
Olympic officials in Italy said bird flu posed no threat to the Turin Olympics, but a Nigerian official warned that bird flu was fast spreading in that country.
A U.N. expert said the strain may have surfaced in a second African country.
Bird flu has killed at least 91 people since 2003, according to the World Health Organization. Almost all the human deaths have been linked to contact with infected poultry, but experts fear the H5N1 virus could mutate into a form that spreads easily among people, possibly sparking a pandemic.
Irans official Islamic Republic News Agency quoted the countrys Veterinary Organization as saying that international laboratory results confirmed the wild swans died from bird flu. It did not name or give the location of the laboratory.
Health Minister Kamaran Bagheri Lankarani said on state-run television that Iranian officials have killed all wild birds in a three-mile radius around where the virus was detected, about 200 miles northwest of the capital Tehran.
Two dead swans in northern Germany were found on the island of Ruegen, and regional agriculture ministry spokeswoman Iris Uellendahl said a preliminary test showed they died of H5N1.
Agriculture Minister Horst Seehofer ordered domestic poultry kept indoors beginning Friday instead of Feb. 20 as previously ordered. Samples from the birds were being taken to an EU laboratory in Britain for a definitive test, Uellendahl said.
Two birds found dead in Austria appear to also have been infected with the H5N1 strain. Hans Seitinger, a health official for Styria province, said there was a 70 percent chance that H5N1 had reached the country, according to results from preliminary tests carried out on samples from 21 birds. Samples have been sent for confirmation to a lab in England.
Health officials in Italy, said they remained vigilant after a deadly strain of the virus was detected in the south of the country on Saturday.
Tests conducted on birds and poultry in this northern region where the Olympics are being held have all come back negative, officials said.
On Saturday, Italy confirmed that six wild swans found in the southern regions of Sicily, Puglia and Calabria tested positive for H5N1. The areas are more than 600 miles from Turin.
The H5N1 strain was first confirmed in Africa last week in fowl in three states in northern Nigeria. Its now suspected in five other states, raising concern Nigeria is not taking the necessary measures to combat the disease.
We have received reports that the disease is fast spreading to other farms across the state, said Shehu Bawa, the head of a bird flu committee in Nigerias northern Kano state.
Niger, Nigerias northern neighbor, has said it was investigating two roosters found dead in a market near the Nigerian border.
Juan Lubroth, a senior animal health officer at the United Nations Food and Agriculture Organization, said, its likely that its H5N1.
Many West African countries have taken measures such as calling on citizens to be vigilant or banning fowl imports to try to stop H5N1 from spreading on a continent with scarce means or infrastructure to deal with a public health crisis.
In Rome on Tuesday, where veterinary experts from the U.N. Food and Agriculture Organization held a briefing on the Nigerian outbreak, the FAOs director said the Nigerian outbreak posed a threat to Europe.
Given the fact that the virus is circulating quite wildly in Africa, where our migratory birds go spend their winter, we may state that there is a risk in the coming spring when wild birds will start migrating north, Samuel Jutzi said.
The virus was first detected in wild swans in Italy and Greece on Saturday the arrival of the strain in the European Union.
Associated Press writer Dulue Mbachu in Lagos, Nigeria, contributed to this report.