A second person from Saudi Arabia has died from a new respiratory illness similar to the SARS virus which sparked a global alert in September, the World Health Organisation (WHO) has announced.
WHO said in a statement that it has been notified of four additional cases, including one death, due to infection with the rare coronavirus.
In 2002, an outbreak of the SARS coronavirus killed about 800 people after it spread from Hong Kong to more than 30 countries around the world.
The additional cases have been identified as part of the enhanced surveillance in Saudi Arabia - three cases, including one death) and Qatar (one case).
This brings the total of laboratory confirmed cases to six, the United Nations health watchdog added.
WHO said it continues to work with the governments of Saudi Arabia, Qatar and other international health partners to gain a better understanding of the coronavirus.
"Further epidemiological and scientific studies are needed to better understand the virus," it added.
Investigations are ongoing in areas of epidemiology, clinical management, and virology, to look into the likely source of infection, the route of exposure, and the possibility of human-to-human transmission of the virus.
Close contacts of the recently confirmed cases are also being identified and followed-up, WHO's statement said.
So far, only the two most recently confirmed cases in Saudi Arabia are epidemiologically linked - they are from the same family, living in the same household.
Preliminary investigations indicate that these two cases presented with similar symptoms of illness. One died and the other recovered.
Additionally, two other members of this family presented with similar symptoms of illness, where one died and the other is recovering.
Laboratory results of the fatal case is pending, while the case that is recovering tested negative for the novel coronavirus.
The WHO urged countries to continue their surveillance for severe acute respiratory infections.
"Until more information is available, it is prudent to consider that the virus is likely more widely distributed than just the two countries which have identified cases," WHO said.
The WHO issued a global alert in September saying a virus previously unknown in humans had infected a 49-year-old Qatari who had recently travelled to Saudi Arabia, where another man with the same virus had died.