Four swine flu cases have been reported in the city since Thursday and a child is among the victims.
West Bengal Health Minister Suryakanta Mishra said on Saturday that all the affected by swine flu were admitted to state-run Infectious Diseases Hospital in the city on Friday after their swabs tested positive.
The victims have been quarantined and ''They are kept under watch,'' the minister said. Asked about steps taken by the authorities to prevent the spead of swine flu, Mishra said "we are taking measures as per the international protocol."
"All hospitals in the city and districts have been asked to adopt preventive measures and open quarantine ward for admission of swine flu patients," officials said.