Monday's drill involved officials at the WHO's Western Pacific regional headquarters in Manila talking by phone with counterparts in Cambodia, Singapore, Indonesia, and Japan.

Officials simulated the dispatch of the influenza drug Tamiflu and protective gear, like goggles and masks, from a Japan-donated stockpile in Singapore to the Cambodian capital, Phnom Penh.

Also Monday, Burma reported a fifth outbreak of bird flu in an area north of Rangoon, the country's largest city.

Authorities have culled at least 40,000 fowl since the virus first appeared in late February.

A state-controlled newspaper , the New Light of Myanmar, reported today that the sale and transport of poultry in the area caused the virus to spread.

The WHO says the H5N1 virus has killed 170 people and infected at least 285 since it first appeared in 2003.

Scientists fear the H5N1 bird flu strain could mutate into a form that could spread easily among humans and lead to a global pandemic with the potential to kill millions.