While authorities in Greece anxiously await test results on eight dead birds found in the northeastern Evros River delta, in another main migratory route, Croatia had also started testing dead birds found by citizens.
Many European countries are struggling to test for outbreaks of deadly bird flu while simultaneously trying to reassure and calm people to avoid widespread panic after the disease was found in Turkey and Romania.
Regardless of Romania's assurances that no new cases had been found, after a mass cull of poultry on Monday, neighboring Bulgaria is preparing a national crisis headquarters after stepping up border controls and surveillance of poultry farms and wetlands near its Danube River boundary.
Bulgaria, which also borders Turkey, confirmed H5N1 among domestic fowl last week, and has tested scores of dead birds.
Speaking in Asia, where more than 60 people have died from the H5N1 strain of avian influenza and the most likely epicenter of any human pandemic, U.S. Health Secretary Mike Leavitt, emphasised the threat of bird flu spreading, and warned no nation was properly prepared for a bird flu pandemic.
In order to get his point home Leavitt spoke of the world as a vast forest, where a spark if seen can be simply snuffed out,but, if allowed to burn for an hour or two hours, becomes an uncontainable blaze.
Although no human cases have as yet been reported in Europe, the World Health Organization is concerned European countries might now divert funding and attention away from Southeast Asia which was the most likely ground zero for any serious pandemic.
The European Union has appealed to countries to test dead birds, while the EU center for communicable diseases is attempting to play down the threat to the public.
Zsuzanna Jakab, the director of the European Center for Disease Prevention and Control (ECDC) said the risk to human health, to public health, at present is minimal.
Peter Cordingley, WHO spokesman in Manila, says the feared mutation of the virus into a form that is easily transmitted between humans, remains most likely in Southeast Asia, where millions of birds were culled to try halt the disease's spread.
The H5N1 strain first emerged in Hong Kong in 1997, when it caused the death or destruction of 1.5 million birds. Eighteen people fell ill, of whom six died. It re-emerged in 2003 in South Korea, and has now spread to China, Vietnam, Thailand, Laos, Indonesia, Turkey and Romania.
To date, according to the WHO, H5N1 has infected 117 people in four countries and killed 60.
Nevertheless, governments insist on vigilance and extra surveillance of birds that could carry the disease.
Montenegro chief veterinarian Ivan Popovic, says that there is no reason to panic and that finding a dead pigeon or sparrow is no cause for alarm, whereas finding several dead ducks or other wetland birds, could be dangerous.
Cordingley, while acknowledging the anxiety in Europe, says the worry is that governments might focus on domestic preparedness and forget the fact that ground zero is in fact Southeast Asia.
Health experts report that the fight against bird flu in Asia is being considerably hampered by huge differences in wealth between countries and some that have poor public health infrastructure.
Some still have no stockpiles of the expensive anti-viral drugs that could help limit a human pandemic.
Swiss drugs company Roche said on Monday it was donating packs of its anti-influenza drug Tamiflu to Turkey and Romania after the disease was found in mainland Europe.
Roche, which has said it is increasing production of Tamiflu as quickly as possible, has already said it is giving three million packs to the World Health Organization.
The United States has pledged $25 million to Southeast Asia for training, supplies, lab equipment, village-based surveillance systems and public education.