HONG KONG (AP) _ Hong Kong said today it apparently had stemmed an alarming outbreak of bird flu among humans _ but within hours announced the virus had claimed under victim.

Government spokesman Alex Li said the fifth death didn't change the assessment that the slaughter of Hong Kong's 1.3 million chickens had at least partly controlled the spread of the virus.

That was because the victim, a 34-year-old woman who died of pneumonia on Sunday, contracted it before Hong Kong's mass chicken slaughter began at the end of December, Li said.

``The completion of this safe period indicates ... that our efforts to control the main source of infection is, to some extent, effective,'' Li said.

He said the government would remain vigilant for signs of the flu.

Wednesday was the 14th day since the chicken slaughter was largely completed and the last day of a two week high-risk period for the flu.

The government has said that if no new cases of infection occurred within the period, the slaughter would be considered to have largely wiped out the virus in Hong Kong.

So far, five people have died from complications arising from the influenza A H5N1 virus, which claimed its first human victim in May. Thirteen other people have contracted the virus, and one other person is suspected of having it.

Doctors say chickens are the main source of the disease, and that human to human transmission is likely very slow.

Officials Wednesday said they wouldn't order a mass duck slaughter because tests showed ducks were only intermittent carriers.

But Michael Suen, the acting deputy to Hong Kong's leader, said the government would in future not allow ducks to mix with chickens.

Officials say the next major step in controlling the virus is to ensure only healthy birds come to Hong Kong from China.

Chicken imports from mainland China _ from where Hong Kong believes the disease came _ were halted days before the slaughter began. They are banned indefinitely, until the government says it is confident the supply is clean.