"The number of people who contracted the virus in the kingdom since August/September is 24, of whom 15 have died," Rabia told a news conference on Sunday in Riyadh.

An earlier toll provided on Tuesday by the World Health Organization said 11 people had died in Saudi Arabia since last year from the disease whose medical term is NCoV-EMC, or novel coronavirus.

Rabia also said three other people are suspected of having contracted the virus in Saudi Arabia, pledging to announce with "full transparency" the results of their medical tests.

The WHO's assistant director general for health security and the environment, Keiji Fukuda, told a Riyadh news conference on Sunday the new virus posed an "important and major challenge" for countries affected and the world generally.

He said experts were still grappling to understand all aspects of the virus and how humans become infected, stressing, however, that "this new virus is not the SARS virus."

"This is a new infection and there are also many gaps in our knowledge that will inevitably take time to fill in," a WHO statement cited Fukuda as saying.

"The greatest global concern, however, is about the potential for this new virus to spread. Of most concern, however, is the fact that the different clusters seen in multiple countries increasingly support the hypothesis that when there is close contact this novel coronavirus can transmit from person-to-person," he said.

"This pattern of person-to-person transmission has remained limited to some small clusters, and so far, there is no evidence that this virus has the capacity to sustain generalized transmission in communities."

Since the virus was first recorded in September 2012, there have been 34 cases reported worldwide, and 18 of those have died, according to the WHO.

While it has been deadliest in Saudi Arabia, cases have also been reported in Jordan, Germany, Britain and France where two patients are now in hospital in the northern city of Lille.

It is a cousin of Severe Acute Respiratory Syndrome (SARS), which triggered a scare 10 years ago when it erupted in East Asia, leaping to humans from animal hosts and eventually killing some 800 people.