On January 26, Philippine airport authorities placed the Ninoy Aquino International Airport (NAIA) terminals on heightened alert against bird flu, after a number of cases of human infection have been reported in Asian countries since the beginning of the year.

All passengers arriving at the NAIA terminals from abroad must undergo thermal screening before they are allowed to enter the country, the Manila International Airport Authority (MIAA) said.

Until now, only passengers from countries with recorded cases of bird flu were screened.

MIAA said that its medical personnel would make sure that all arriving passengers, including airline crew members, pass through the thermal camera scanners set up at the corridor of the arrival section of the airport.

"Anyone who will reflect an unusually high body temperature as indicated by the thermal scanner will be checked by the medical staff on duty," it said.

The MIAA has also identified a holding area for the aircraft carrying passengers with suspected avian flu cases, while passengers with high temperature will be brought to an isolation area, said the MIAA.

Several new bird flu cases have been reported in China, Hong Kong SAR, Japan, South Korea, Indonesia, Thailand and Vietnam since the beginning of the year.