Italian authorities on Tuesday ordered the cull of 20,000 turkeys after an outbreak of avian influenza was confirmed in a farm in the northeast of the country.

According to the epidemiological surveillance service of the Veneto region, the outbreak was discovered in the farm at the outskirts of the town of Mira in Venice province on Saturday.

“Preventative seizure of the farm was adopted immediately to avoid the spread of the disease, and the presence of the highly contagious H5N8 virus was confirmed by health authorities.

“Of the 20,500 turkeys overall at risk in the commercial farm, some 6,000 were infected, and 600 died of the virus,’’ the Italian health authority for animal health and food safety said.

The mayor of Mira said in a statement that as a result, it had ordered the “immediate slaughter of all captive turkeys on the site”.

City authorities also upheld the seizure of the factory, and imposed a strict sanitary surveillance zone around it.

As due in such cases, the Italian government has reported the outbreak to the World Organisation for Animal Health in Paris.

“The outbreak is the first detected among poultry.’’

Also on Monday, the H5N8 virus was confirmed in a wild swan, which had been found dead in the province of Gorizia at the border with Slovenia.

Italy had already reported three bird flu cases with different variants of the virus in wild birds in the northeast on Dec. 28, Jan. 5 and Jan. 10.