The infected cats were found in Poznań, the tri-city metropolitan area, and Lublin, locations separated by hundreds of kilometers. Nine cats have been confirmed to be infected with the H5N1 subtype of avian influenza in Poland, the country's Chief Veterinary Officer announced on Monday, as reports of mammals being infected with the virus continue to increase.

The infected cats were found in Poznań, the tri-city metropolitan area, and Lublin, locations separated by distances of hundreds of kilometers. According to the Chief Veterinary Officer, initial investigations found that the virus the cats were infected with is not the same strain as the virus that has been infecting gulls in the country in recent weeks.

The source of infection for the cats had not been identified as of Monday. The Polish General Veterinary Inspectorate is working to establish a protocol for monitoring bird flu spread in cats and advised residents to keep cats indoors if possible, prevent contact between cats and wild animals, prevent cats from coming into contact with footwear, feed cats only with food from known sources, and wash their hands after coming into contact with animals.

The reports from Poland come as reports of mammals being infected with avian influenza continue to spread across the globe, with mass die-offs of seals and sea lions reported in Russia and the Americas and dozens of foxes, skunks, dolphins, raccoons, cats, ferrets and other mammals found to be infected as well.