European Health Commissioner Androulla Vassiliou Friday expressed her concern on the sharp increase of A/H1N1 flu cases in north Europe with the onset of cold weather.

"We are very worried both at the number of new cases and the big number of deaths because of the flu," the Cypriot commissioner told reporters in Nicosia.

She said they were especially worrying about Ukraine, where flu cases more than doubled in a couple of days and deaths also rose remarkably.

"The virus is not contained by borders. We have already appealed to other countries for help to Ukraine," though it is not an EU member, she said.

Vasilliou urged people to take vaccines, which she said have been proved safe.

"Those having cardiac problems and diabetes and pregnant women must be given a priority" in being vaccinated, she said.