As Japan reported more A/H1N1 flu cases among students and shutting schools, the government of Macao Special Administrative Region (SAR) Monday decided to raise the pandemic alert phase from level IV to V, stepping up the prevention measures against the flu.

Level V is only one step from the highest phase under Macao's alert system. With the higher alert level announced, direct flight passengers from Japan, in addition to Mexico, United States and Canada, will be required to undergo medical tests upon arriving at the Macao International Airport, and local students will need to test their body temperature before entering their schools, while those previously adopted measures will continued to be exercised, the SAR's Health Bureau said.

Meanwhile, the Bureau also said that a 31-year-old and a 24-year-old local female residents who showed flu symptoms after flew back to Macao respectively from Canada en route US and directly from the US recently have been ruled out of being infected with the A/H1N1 flu.

In addition, five people who had close contact with Hong Kong's third confirmed A/H1N1 flu patient and entered Macao later were also ruled out of being infected with the A/H1N1 flu after preliminary lab tests, but they will still be quarantined in Macao till May 23 for safety reasons, according to the Bureau.

As of 6:00 GMT on Monday, 40 countries have officially reported 8,829 cases of influenza A/H1N1 infection, of which six were found in China and 125 were confirmed in Japan, according to the World Health Organization (WHO). No such case was detected in Macao by far, according to the SAR' Health Bureau.