China's health ministry has confirmed that a 19-year-old woman died of the H5N1 bird flu virus in Beijing, the World Health Organisation (WHO) said on Tuesday.

China recorded three bird flu cases last year, all fatal.

The bird flu virus is constantly mutating, and experts fear it could change into a form that is easily transmitted from person to person and kill millions of people worldwide.

At present, H5N1 remains mainly a bird virus, but WHO data released in mid-December showed 247 people had died from it out of 391 cases since the virus resurfaced in Asia in 2003.

'We received confirmation of the case from the Chinese health ministry. A 19-year-old woman died on Monday in Beijing of H5N1,' WHO spokesman Gregory Hartl said in Geneva. He had no further information.

Earlier, the Beijing Municipal Bureau and Hong Kong's government gave more details of the latest case.

'The woman fell ill on Dec. 24, was hospitalised on Dec. 27 and died on Monday (at) 7.20 am,' the bureau said in a faxed statement. - Reuters