Another person has died of a mysterious respiratory virus and three more cases have been discovered in Saudi Arabia and Qatar, the World Health Organization said Friday.

“This brings the total of laboratory-confirmed cases to six,” the Geneva-based UN agency said in a statement.

A Saudi man died from the novel coronavirus in June and a Qatari man was hospitalized in London with the virus after a trip to Saudi Arabia.

The WHO has previously confirmed that the new strain was part of the coronavirus family, which also includes the deadly SARS virus as well as the common cold.

What sets the new virus apart from SARS is that it causes rapid kidney failure, the WHO said.

In view of the small number of cases with little connection between them, the WHO has previously said the virus did not appear to be very contagious, but it stressed Friday that many cases might be going undetected.