Chickens at a central Polish poultry farm have tested positive for the deadly H5N1 strain of bird flu, authorities said Monday.

It was the country's second case of the deadly virus in domestic livestock after another farm nearby reported an outbreak earlier this month.

Agriculture Minister Marek Sawicki said the new outbreak occurred at a farm of some 360,000 chickens in the village of Sadlowo, northwest of Warsaw. He did not say how many birds were infected.

Authorities ordered farmers in the area to keep poultry indoors and launched inspections of farms within three kilometers (two miles) of the outbreak.

The H5N1 strain was first detected in Poland in wild swans last year.

The disease has ravaged poultry stocks in Asia, and scientists believe it spread to Europe and to Africa with migratory wild birds.