Romanian authorities have found cases of suspected bird flu in fowl close to the Black Sea port of Constanta.
Avian flu has been discovered in 29 villages across the country since the virus was first detected in the Danube delta in October, but Romania has not reported any human cases.
"Rapid tests on two dead hens found in a courtyard led to suspicion of the presence of the H5 type of the virus in the Topraisar village, in the county of Constanta," the country's chief veterinarian said. The village is 40 kilometres north of the border with Bulgaria.
All 20 hens from the courtyard were killed. The village will be quarantined, and birds will be culled there if further checks confirm the presence of the H5 type.
On Saturday, authorities found new suspect bird flu cases in the delta and confirmed the presence of the virus in a nearby village.
Last week, Romania confirmed the presence of the H5 type in poultry in a village in the south of the country close to the border with Bulgaria.
The delta is Europe's largest wetlands and lies on a major migratory route for wild birds, believed to be the carriers of the virus in its highly pathogenic form.
H5N1 has killed at least 88 people and caused the death of millions of birds since 2003.