A man in southern China's Guangdong province has died of bird flu a week after being admitted to hospital with a fever, state media reported.

It is the nation's first reported human case of the deadly disease in 18 months.

The 39-year-old who lived in Shenzhen, just across the border from Hong Kong, developed symptoms on 21 December and was admitted to hospital on 25 December because of severe pneumonia, the official Xinhua news agency said.

He died in the early afternoon, having tested positive for the H5N1 virus, the brief report added.

Guangdong's official newspaper, the Southern Daily said separately that 120 people who had contact with the man had developed no signs of sickness.

About 10 days ago Hong Kong culled 17,000 chickens at a wholesale poultry market and suspended all imports of live chickens from mainland China for 21 days after a dead chicken there tested positive for the H5N1 virus.

The virus is normally found in birds but can jump to people who do not have immunity to it.

In recent years, the virus has become active in various parts of the world, mainly in east Asia, during the cooler months.

Authorities in China are worried about the spread of infectious diseases around this time when millions of Chinese travel in crowded buses and trains across the country to go home to celebrate the Lunar New Year.

The current strain of H5N1 is highly pathogenic and kills most species of birds.

Since 2003, it has infected 573 people around the world, killing 336.

The virus also kills migratory birds but species that manage to survive can carry and disperse the virus to new, uninfected locations.

It transmits less easily between people but there have been clusters of infections in people in Indonesia and Thailand in the past.