Clinic director Johann Altenberger confirmed on Sunday that out of 20 influenza patients, four have been diagnosed with the H1N1 virus.
He said that it was not an aggressive form of the virus and that “all safety precautions” are being taken. The patients with swine flu have been isolated and clinic employees are wearing face masks to protect against infection.
Relatives and friends of patients have been banned from visiting the clinic.
At least 50 people are reported to have died of swine flu in Russia this year and there has also been an outbreak in Ukraine, where the virus has killed around 60 people. An outbreak in Iran has reportedly killed 112 people since December.
Swine flu first appeared in Mexico in 2009 and rapidly spread around the world.