Two professionals aged 37 and 22 from Pune, who come from Spain and US respectively, have been kept under observation at the Naidu hospital on Monday.

Both of them showed symptoms of deadly H1N1 flu.

The suspected cases are of two young males aged 37 and 22 who were referred to the Sassoon authorities by a private hospital where they had gone for treatment complaining of sore throat yesterday, Dr Arun Jamkar, dean, Sassoon hospital told PTI.

According to reports, the throat swab samples of suspects have been forwarded to the National Institute of Virology (NIV) for lab tests.

The reports of the same will be available within 24 hours.

Nitin Bilolikar, civil surgeon of the state health services, said that they landed in Mumbai early on Monday morning, and traveled to Pune in different taxis.

Mr. Bilolikar added, "Both of them developed symptoms like fever and sore throat on reaching home. They went to private hospitals, which referred them to the Naidu hospital, where a provision of a 20-bed quarantine ward has been made by the state health services following the flu outbreak."

Sachin Desai, medical officer (epidemic) of the state health services, also stated that both the persons were free of any Swine flu symptoms when they were tested at the Chhatrapati Shivaji International Airport in Mumbai.

Health department functionaries said that 531 passengers have been tested at the airport since May 3.

But, no one has thus far been detached at the airport for such symptoms in Pune.