The 19-year-old soldier, who was diagnosed with avian bird flu on May 18, has died, after a group of medical experts failed to save him from physical deterioration, confirmed the Information Office of Chinese Ministry of Health on Tuesday in a fax statement to chinadaily.com.cn.

Full coverage: Bird Flu  Related readings: Soldier hospitalized with bird flu Vietnam reports more bird flu in poultry Girl dies, man in hospital in Asia bird flu cases Bird flu hits village in Hunan Province Bird flu outbreak confirmed in Hunan SFDA approves second-phase trials for bird flu vaccine China to share bird flu samples Boy, 16, dies from bird flu

The soldier, surnamed Cheng, was serving in the People's Liberation Army (PLA), but the Information Office declined to say in which area of the country Cheng was stationed, or how he may have come in contact with the virus, citing military confidentiality.

People who had close contact with Cheng have not developed any clinical abnormalties. The office added medical observations of these people have stopped.

"People who had come into close contact with the victim have not shown any manifestations (of bird flu) so the medical observations have been lifted," the ministry statement said.

According to earlier reports, Cheng developed a fever, cough and pneumonia on May 9. He was sent to an army hospital on May 14 and remained there until he died.

According to the WHO Beijing Office, the soldier died on Sunday, but the Health Ministry did not provide a specific date.

Joanna Brent, a Beijing-based spokeswoman for the WHO, said the health body was not concerned about an epidemic, according to an AFP report.

"This is the third case in China this year. Three individual cases in a country of more than a billion people is not a cause for alarm," she said.

Brent praised China's prompt reporting of avian influenza outbreaks.

"We have been pretty comfortable with the reporting of recent cases," she said.

"There is nothing to suggest that there is an increased threat to humans. However, obviously the virus is still present in China, and we need to remain vigilant," she said.

Tests by the local Center for Disease Control and Prevention (CDC) on May 18 showed that he was infected with the H5N1 strain of the bird flu virus. The CDC and the State confirmed the result on May 20.

Since 2003, China has reported 25 human cases of bird flu, which have led to 15 deaths.

On March 27, a 16-year-old boy in eastern Anhui Province died from the deadly virus. The cause of his infection is still unknown.

Another reported human cases of bird flu this year was Li Yinxiu, a farmer in Fujian, who had developed symptoms after coming in contact with dead poultry. She had been discharged On May 29 from the hospital after three months of treatment.

The Ministry of Health confirmed last August that the country's first human case of H5N1 bird flu virus had occurred in November 2003. A 24-year-old man who died in Beijing in 2003 was initially thought to be suffering from SARS. Further laboratory tests later confirmed he had died of avian influenza.

The H5N1 bird flu virus is rare for humans to get from animals, but experts fear it could mutate into a form that could easily spread among people, potentially sparking a pandemic.

Sinovac Biotech, a Beijing-based pharmaceutical company is experimenting with a bird flu vaccine, and in April, the State Food and Drug Administration approved the second phase of clinical trials of the vaccine.