A total of 59 pneumonia cases have been confirmed during the latest outbreak in the Chinese city of Wuhan, the local health commission reported on Sunday.

The root cause of the outbreak is still under investigation, but SARS, MERS and bird flu have all been ruled out.

"As of 8 a.m. on January 1, 2020, the commission was informed of 59 pneumonia cases, of which 7 were in critical condition. All the 59 patients are alive and being treated in hospitals," the commission said on its website.

The city government is actively searching for other potential patients and looking for the root cause of the outbreak.

The commission also suggested that residents in Wuhan maintain airflow indoors and wear masks if needed.