Health authorities in the central Chinese city of Wuhan are reporting the first death from a new type of coronavirus. The others were in stable condition and at least two had been released from a hospital.
The Sars epidemic originated in China, infected more than 1,700 people in Hong Kong and killed almost 300.
In Singapore, the Ministry of Health said on Saturday that a second suspected case - a 26-year-old China national with pneumonia and travel history to Wuhan - was found not to be linked to the pneumonia cluster in Wuhan.
There have been no new cases reported since January 3 and no indication of the disease transmitting among humans, authorities said.
Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to SARS.
Scientists in Hong Kong's Department of Health said Saturday that genetic sequencing of the virus found in one of the Wuhan patients and published online by a Chinese expert indicated it was 80 percent similar to SARS found in bats.
Hong Kong authorities have taken a range of precautions including stepping up the disinfection of trains and planes, and checks of passengers. Authorities have closed the seafood market.
A restaurant on the outside of the building housing the seafood market was still open for business. Shortness of breath, chills and body aches are associated with more risky kinds of coronavirus, according to the U.S. Centers for Disease Control and Prevention.
It said he died after his heartbeat stopped on Thursday night.
The emergence of the virus is raising concerns as hundreds of millions of people are getting ready to travel during the Chinese New Year holiday later this month. Cases have originated from several provinces and municipalities across mainland China, and there have been a small number of avian influenza cases among Hong Kong SAR and Taiwan residents who have traveled to mainland China.
Forty-six of that total, however, have already been discharged.
'The UK has robust arrangements to manage emerging diseases and we can draw on our experience of developing pioneering diagnostic tests in humans for the coronaviruses - SARS and MERS'.
Numerous patients had worked at a seafood market where wild animals such as pheasants and snakes, as well as rabbit organs, had also been sold.