A 61-year-old man has died from pneumonia in the central Chinese city of Wuhan in an outbreak of a yet to be identified virus while seven others are in critical condition, the Wuhan health authorities said on Saturday.

In total, 41 people have been diagnosed with the pathogen, which preliminary lab tests cited by Chinese state media earlier this week pointed to a new type of coronavirus, the Wuhan Municipal Health Commission said in a statement on its website.

More:

Two of them have been discharged from hospital and the rest are in a stable condition, while 739 people deemed to have been in close contact with the patients have been cleared, it said.

The man who died was a regular buyer at the seafood market, and had been previously diagnosed with abdominal tumours and chronic liver disease, it said.

Treatments did not improve his symptoms after he was admitted to hospital and he died on the evening of January 9 when his heart failed.

The commission added that no new cases had been detected since January 3.

The Wuhan health authority also said that the patients were mainly vendors and purchasers at a seafood market in the city, and that to date, no medical staff had been infected, nor had clear evidence of human-to-human transmission been found.

The World Health Organization said on Thursday that a newly emerging member of the family of viruses that caused the deadly Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) outbreaks, could be the cause of the present outbreak.

Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to SARS. Some of the virus types cause less serious disease, while some like the one that causes MERS, are far more severe.

The outbreak comes ahead of the Lunar New Year holidays in late January, when many of China's 1.4 billion people will be travelling to their home towns or abroad.

The Chinese government expects passengers to make 440 million trips via rail and another 79 million trips via aeroplanes, officials told a news briefing on Thursday.

The Wuhan health authority in its statement also urged the public to take more precautions against infectious diseases and said it was pushing ahead with tests to diagnose the pathogen and, as of Friday, had completed nucleic acid tests.