Ukraine has declared a state of emergency in the Crimea peninsula as it seeks to halt the country's first outbreak of bird flu.
Five villages have been placed under quarantine and all poultry in the affected regions will be slaughtered.
Health experts investigating the death of 1,600 domestic birds in the area earlier confirmed the presence of a strain of the H5 virus.
Further samples are being sent to Britain and Italy for study.
It is not known yet if the outbreak is of the H5N1 strain which has killed nearly 70 people in Asia.
President Viktor Yushchenko took the emergency measures decision at a special meeting with key ministers.
"Today we must show solidarity and mutual understanding throughout the country, and carry out effective measures to combat this illness in the affected region," he said.
The outbreak is being blamed on migratory birds
The Interior Ministry is sending troops to secure the area, Ukrainian television reported.
Local health officials said that domesticated chickens and geese began dying in the Sovetsky and Nizhnegorsky districts three days ago.
People who had come into contact with the dead birds were being monitored, the authorities said.
Agriculture Minister Oleksander Baranivsky said officials had identified a third region, but were still waiting for a diagnosis, the Associated Press news agency reported.