All the villages were located near the east coast of Ukraine's Crimea peninsula, only kilometres from another eight villages with widespread bird flu infections confirmed over the weekend.
Household chicken, ducks, and geese in the villages Akimovka, Krasnoflotnoe, Dmitrovka, and Chernozemnoe were the main victims of the outbreak, and suffered symptoms similar to bird flu, Sehodnia newspaper reported.
The overnight death rate was, as in previous cases of bird flu, over ninety per cent, the Interfax news agency reported.
The most likely cause of the new deaths was the spread of bird flu into previously unaffected areas, despite a government quarantine on infected villages in place since Monday, said Mykola Patsiuk, director of Ukraine's department of veterinary medicine.
Poultry carcasses were being tested for the presence of bird flu, and if confirmed the quarantine would be expanded to the four villages, Patsiuk said.
Ukraine health authorities since the beginning of the outbreak have destroyed more than 28,000 domestic birds in the Crimea province, in an effort to limit the area infected by the disease.
Local media are blaming the government for a sluggish response to the movement of the bird flu virus, which had been identified in neighbouring Romania, Turkey and Russia up to two months previously.
Crimean health officials ignored warning signs migrating birds had infected domestic poultry as long ago as October, and waited only until late November before admitting bird flu had arrived in Ukraine, Inter television reported.
Ukraine President Viktor Yushchenko sacked the country's top veterinary officer in the wake of the scandal.