Ukraine on Sunday began combating what appeared to be the biggest outbreak yet in Europe of the deadly strain of bird flu, after more than 2,000 domestic birds died in a remote region of the Crimean peninsula.

President Viktor Yushchenko declared a state of emergency in five villages on Saturday after the agriculture ministry said it had identified the H5 subtype of bird flu virus. Officials enforced a quarantine and began culling and burning the villages’ birds on Sunday.