Five Saudis have died of a new Sars-like virus during the past few days and two more are being treated in an intensive care unit, the Saudi Health Ministry said.
All seven of the cases occurred in al-Ahsa area of the kingdom's oil-rich Eastern Province, according to a ministry statement cited last on Wednesday by the Saudi Press Agency.
Known as the novel coronavirus, or hCoV-EMC, the bug was first discovered last year and is related to the severe acute respiratory syndrome disease, which triggered a pandemic scare across East Asia a decade ago, killing 299 in Hong Kong.
The Health Ministry said that it was taking "all precautionary measures for persons who have been in contact with the infected people … and has taken samples from them to examine if they are infected." However, the ministry gave no figures for how many people have been examined to see if they have the lethal disease.
Sixteen of the 23 people diagnosed with the disease in Britain, Jordan, Germany and Saudi Arabia have died. Saudi Arabia has accounted for most of the deaths, with 11 in all, including the five new fatalities.
Coronaviruses cause most common colds and pneumonia, but are also to blame for unusual conditions such as Sars, which infected nearly 8,100 worldwide, with 774 confirmed deaths.
The new virus is different from Sars, in that it can cause rapid kidney failure. The World Health Organisation (WHO) does not yet know how the mysterious strain is transmitted or how widespread it is.
The WHO said a 73-year-old Saudi man died in Germany in March from the lethal new virus. He had been travelling in Pakistan and Saudi Arabia and was transferred to Munich from Abu Dhabi on March 19.
Researchers believe the virus can be transmitted from human to human, although such occurrences appear to be uncommon.
Current research has been limited to studying cases in people who have been hospitalised with severe illness.
It remains unknown whether the disease is truly rare and acute, or if it may be more abundant but mild so as to escape detection most of the time.