BEIJING (Reuters) - Chinese healthcare authorities in Wuhan said an outbreak of viral pneumonia was not Severe Acute Respiratory Syndrome (SARS), Middle East respiratory syndrome (MERS) or bird flu, and that they were still working to identify the cause and source.

In a statement posted on its website Sunday night, the Wuhan Municipal Health Commission said a total of 59 cases of unknown viral pneumonia had been reported as of Sunday, including seven in a critical condition. It also said it had put 163 people who had had contacts with the patients under medical observation.

The viral pneumonia started in the central city of Wuhan late last month, prompting fears of a possible SARS epidemic.