Singapore is not ruling out the possibility of restricting visitor numbers at hospitals as a precautionary measure against the swine flu outbreak, the country' s Health Minister said on Monday.

Singapore's Health Minister Khaw Boon Wan said that whether his ministry will take this measure will depend on what develops over the next couple of days, according to local radio 938 live's report.

"If you do not have to visit hospitals, don't visit because it is not exactly a clean place," Khaw said. He also called on Singaporeans to maintain a high level of personal hygiene, and postpone or avoid non-essential travel to affected flu outbreak areas.

There are currently no known cases of human swine flu in Singapore.