The four cases of "pneumonia without definite cause" reported in Beijing over the past week are not due to H7N9 infection or SARS, according to the city's Center for Disease Control and Prevention.

The center ran tests on the four patients because local hospitals are on the alert for H7N9 infections, Pang Xinghuo, deputy director of the center, said on Monday.

Beijing health authorities have ordered local medical institutions to report pneumonia cases immediately, and tests must be conducted to determine the cause.

Also, hospitals that suspect a patient might have been infected with the H7N9 virus must report the case within two hours.

In 2007, the National Health and Family Planning Commission issued guidelines for medical institutions nationwide to follow in order to detect SARS and human infections of bird flu virus.

Under the guidelines, "pneumonia without definite causes" and severe pneumonia that does not respond to antibiotic treatment and whose pathogens cannot be determined should be reported to the National Disease Reporting System. Those reports are sent to the National Center for Disease Control and Prevention.

The health of more than 86,000 locals thought to be at risk of getting bird flu, such as butchers and farmers, is also being tracked, according to Pang.

On Sunday, the center released a public information guide to raise awareness of the H7N9 virus. It advises people to avoid contact with birds and chicken, especially those that have died from disease, and to wear gloves when handling poultry if their hands are scratched.