The lethal H5N1 bird flu strain has been detected in birds in northern Cyprus - the island's first cases - the European Commission says.
Turkish Cypriot authorities have slaughtered about 1,500 poultry
The commission has ordered an immediate freeze on the transfer of live animals or animal products across the island's Green Line border or to the EU.
Neighbouring Turkey has been battling with an outbreak of the H5N1 strain, which has killed at least four people.
The lethal strain has killed about 80 people, mostly in Asia, since 2003.
A mass cull of poultry has taken place near Famagusta, eastern Cyprus, where the infected birds are believed to have originated.
The World Health Organization has not confirmed the positive test results, which were carried out at a specialist laboratory in Weybridge, UK.
There have been no human cases of bird flu reported in the outbreak.
Scientists fear the H5N1 bird flu virus could mutate from a disease that largely affects birds to one that can pass easily between people, leading to a human pandemic.