Singapore  - In light of the outbreak of swine flu cases in Mexiko and the United States since Monday all passengers arriving at Singapore's main Changi airport are being screened for flu symptoms.

Thermal scanners at the arrival halls measure the temperature of passengers just before they undergo immigration checks, the Ministry of Health and the Civil Aviation Authority said in a joint statement.

Passengers with higher-than-normal temperature would undergo a more thorough medical assessment.

On Wednesday body heat scanners would also be deployed at the Budget Terminal and at Singapore's Seletar airport.

The precautionary checks were non-intrusive and unlikely to cause any delays, the authorities said.

Although Singapore has so far not reported any incidence of the virus, Health Minister Khaw Boon Wan said it was "better to play safe."

Reports that the virus spread to parts of the US were a reason for concern.

"It does not mean that it'll definitely become a pandemic. But it's better to play safe and assume the worst, rather than hoping the worst will never come and when it does, it's too late to respond," the Straits Times newspaper quoted the minister as saying.

Singapore had learned from the Sars outbreak in 2003 that it's "better to be proactive than behind the curve."

The Agri-Food and Veterinary Authority of Singapore said even though the is no danger of contracting swine flu from pork, it will test pork imports from the US as well as other sources for flu virus as a precautionary measure.

Singapore only imports pigs from a farm located on Pulau Bulan in Indonesia, the authority said. It would also step up surveillance testing of the pigs coming from there. (dpa)