"Deaths of domestic birds have been discovered in six more villages," Volodymyr Ivanov, spokesman for the local branch of ministry, was quoted as saying.
Ivanov described the deaths as "massive," but declined to specify the number. Tests were underway to determine the cause of death, he said.
The six villages are in Crimea's northeast, the same region where on Saturday tests confirmed the H5 virus in poultry in five villages where birds began dying en masse late last week. More than 28,300 birds have been culled, reports the Ukrainian news agency UNIAN.
Samples had been sent to laboratories in Britain and Italy to establish if the virus is of the deadly H5N1 strain, which has killed almost 70 people around Asia over the past two years, with results expected later this week.
Ukraine's President Viktor Yushchenko declared a state of emergency in the affected areas of Ukraine's southern peninsula in the Black Sea and the villages where the H5 virus has been confirmed have been placed under quarantine.
Experts believe the poultry contracted the virus from wild birds, millions of which use the nearby 1,000-sq.-mi. Sivash saltwater lake along the northeastern coast of the peninsula as either a wintering site or a stopover point on their Winter migration route.
UNIAN reported that two hospitals in the Ukrainian capital of Kyiv have been ramped up to treat human cases of avian influenza.