Bulgaria's veterinary service confirmed Friday an outbreak of Newcastle disease in poultry in the northwest of the country, the farming ministry said in a statement.
Local veterinary authorities in the village of Kravoder sent bird samples for testing to the national lab Tuesday after 33 birds in two separate farms died with Newcastle-like symptoms, it said.
The national lab in Sofia confirmed Friday that the birds had died of the milder version of bird flu which is highly contagious among birds but poses no hazard to humans.
The remaining 53 birds at the two farms had been preventively killed.
Local veterinary authorities closed the poultry slaughterhouse in Kravoder and also planned to vaccinate some 24,000 birds in farms in nearby villages over the weekend to prevent a spread of the disease, the statement said.