The victim, identified only by her surname, Li, was a migrant worker in Shanghai. She showed symptoms of fever and pneumonia on March 13 and died on March 21.

The Shanghai Municipal Center for Disease Control and Prevention confirmed Li's blood samples tested positive for H5N1. The municipal health department had suspected she was suffering from bird flu.

The national Center for Disease Control (CDC) re-tested on Thursday Li's samples which were also positive. The tests were made in accordance with the standards of the World Health Organization (WHO), said the ministry.

Those having close contacts with Li have been put under medicalobservation by local health authorities. So far, none have reported abnormal symptoms.

The report did not say how or where the victim might have been infected with the disease and there has been no confirmation on any outbreak of bird flu among poultry in the city.

The ministry has reported the case to the WHO, the regions of Hong Kong, Macao and Taiwan, and several countries.

Li's death brings the total number of human cases of bird flu in China to 16. Ten of the victims have died.

Worldwide a total of 185 human cases of bird flu which caused 104 deaths have been reported to the WHO as of Friday, according to the WHO's website.

There is still room for improvement in China's bird flu surveillance and early warning of the public following bird flu outbreaks, Shigeru Omi, WHO regional director of the Western Pacific, said on Wednesday in Beijing.

Shanghai's health authorities have intensified surveillance andpreventive measures in the city which has a population of about 18million people.

The city's 160 medical departments with fever outpatient service have stepped up screening of patients. Control of animal and poultry trade have also been tightened.

Booklets on bird flu prevention have been sent to communities in a bid to raise public awareness of the disease.

"There's no need to panic, but it's necessary to pay close attention to personal hygiene and avoid contact with sick or dead poultry," said Zhang Yongxin, a professor with the Huashan Hospital under the Fudan University in Shanghai.

Experts have been worrying that the bird flu virus could mutateinto a form that could easily spread among people, causing a global pandemic.

China has agreed to share virus samples from bird flu outbreaksin poultry with WHO to help develop anti-bird flu drugs and vaccines, according to WHO officials.

The first batch of 20 samples should arrive at WHO's overseas laboratories within weeks, said Julie Hall, Coordinator of Epidemic Alert and Response in WHO's Beijing office.