Hong Kong is already checking the temperatures of travellers returning from China at airports, railway stations and ports in a bid to control the spread of the mystery illness.

People arriving with symptoms such as fever, cough or cold could now be quarantined as a protective measure.

Lam's new preventive measures mean schools and workplaces must comply with more intensive cleaning operations and share information with government departments.

"Currently no serious pneumonia case related to Wuhan has been detected in Hong Kong, but the cluster of viral pneumonia cases in Wuhan can be regarded as a 'Novel Infectious Disease of Public Health Significance,'" food and health secretary Sophia Chan said in a statement.

The infection was first reported last week in Wuhan.

As of Sunday, 59 people had been diagnosed. Seven patients were in critical condition, according to the Wuhan Health Commission.

Hong Kong also reported 16 suspected cases of the mystery pneumonia on Sunday, according to public broadcaster RTHK, although none of the patients had reported visiting Wuhan city.

The outbreak has triggered concerns of a resurgence of SARS - severe acute respiratory syndrome - which killed more than 800 people worldwide after it broke out in southern China in 2002.

Health authorities have ruled out influenza, bird flu, Middle East Respiratory Syndrome or SARS.

The World Health Organisation (WHO) has begun monitoring the outbreak.

Australian Associated Press