The city's health department has set up 160 monitoring stations at the fever clinics, where all the fever patients were required to receive treatment.

In addition, all the hospitals were ordered to take measures, such as isolating suspicious human cases and strengthening disinfection, and to give medical workers training on the fatal disease.

Booklets detailing preventative measures have also been handed out to the citizens.

"There's no need to panic, but it's necessary to pay close attention to personal hygiene and try to avoid crowded places," said Zhang Yongxin, a professor with the Huashan Hospital under the prestigious Fudan University in Shanghai.

The woman, a migrant worker, was suffering from a cough and a fever when she was admitted to hospital on March 15. She later died of an unidentified type of pneumonia on Tuesday.

Experts from the city's health department on Wednesday performed multiple tests and analyses on the case and made a preliminary conclusion that the pneumonia was probably caused by the highly pathogenic avian influenza virus.

The department said it has already reported the case to the Ministry of Health, asking experts for a further diagnosis.

If it is confirmed, the case would be the first human infection of the virus in Shanghai, which has a population of nearly 18 million people.

According to the department, people who have had close contact with the dead woman are undergoing medical examinations, but no infectious symptoms have been detected.

China has so far confirmed 15 cases of bird flu in humans, including ten deaths.

Shanghai last had an outbreak of the disease among poultry in 2004.