HONG KONG — Hong Kong has stockpiled antiviral drugs for 350,000 people and hopes to eventually acquire enough for two million people to help defend against a potential flu pandemic, an official said Tuesday.

The drugs that have been collected so far would be used for treating infected patients, health workers and people culling diseased birds in this city of 6.9 million, Dr. Thomas Tsang, a Department of Health consultant, said at a news conference.

Health experts have warned that the H5N1 bird flu strain could mutate into a form that can be easily transmitted between humans and cause a global pandemic that could kill millions.

"No one can really guarantee the anti-virals will work against the upcoming pandemic strain," Tsang said.

"Right now, we have about 3.5 million capsules. And we anticipate over the next few months, during the first quarter of next year, we'll be able to get an additional four million doses and our final target will be about 20 million doses," he added.

Tsang said the government is negotiating with drug companies to expedite the delivery of the medication. Researchers predict that each person infected would need to take a course of 10 pills.

Meanwhile, microbiologist Yuen Kwok-yung warned the Hong Kong public against stockpiling Tamiflu -- one of the only drugs effective against the bird flu virus -- on their own. Local media reported last week that pharmacies in Hong Kong have dramatically marked up prices of Tamiflu because the public rushed to snap up the drug amid bird flu fears.

"We strongly advise the public against self-medication with anti-viral agents," Yuen, said during the news conference.

"That actually increase the amount of resistance in the virus leading to ... treatment failure," he said.

The world's first outbreak of bird flu in humans was recorded in Hong Kong in 1997, when the disease infected 18 people and killed six of them. The latest global outbreak of bird flu has largely spared Hong Kong.