Four hens found dead in a small village of Caraorman had tested positive for the H5 type of bird flu, the authority said, adding that the samples would be sent to Britain to determine if it was the virulent H5N1 strain.
"We have discovered four hens tested positive for the H5 virus in the village of Caraorman," said authority spokeswoman Alina Monea.
Monea said the village, which has no road access, would be quarantined and 2,000 domestic birds would be slaughtered. She did not say when the results of the tests would be known.
The Balkan state last month became the first country in mainland Europe to detect the deadly H5N1 virus in poultry in two villages in the Danube delta, Europe’s largest wetlands near the Black Sea.
Several migratory birds, which use the delta to rest on their way south, have also tested positive for the disease in the past month.
The H5N1 strain has killed more than 60 people in Asia since 2003 and led to the slaughter of millions of domestic birds as scientists feared the virus might mutate into a form that could be easily transmitted between humans.