The Wuhan coronavirus spread further through Iran on Friday, with a total of 13 new cases reported in several other cities besides Qom, where the first infections were reported this week.

There may also be an Iranian connection to what Canadian officials described as a “sentinel event,” the first confirmed case of infection in a person who has never visited China or had contact with people who did. The Canadian patient did recently travel to Iran.

Iranian state media reported on Friday that infections have been detected in Tehran, Babol, Isfahan, Rasht, and other cities in addition to Qom, where four of the first five cases originated. The fifth was an individual from Qom who began displaying symptoms while visiting the city of Arak. A total of 13 new cases were reported, seven of them in Qom.

Health Ministry official Minou Mohrez said the coronavirus outbreak may have begun in Qom and been spread to other cities by travelers. “It’s possible that it exists in all cities in Iran,” she warned.

Mohrez also gave the first official indication of how the virus reached Iran. “It’s clear that new coronavirus has circulated in the country and probably the source of this illness was Chinese workers who work in the city of Qom and had traveled to China,” she stated.

Voters in Iran’s parliamentary election, already suffering from low turnout because the public views it as rigged in favor of hardline theocrats, were photographed at the polls in Qom wearing protective surgical masks.

Canadian officials on Friday reported that a woman in her 30s who recently returned to British Columbia from a trip to Iran has been tentatively diagnosed with the Wuhan virus, becoming Canada’s ninth known infection.

The case was interpreted as an “indicators that there’s more widespread transmission,” according to health official Dr. Bonnie Henry. Final results from testing at one of Canada’s national laboratories are still pending.

The World Health Organization (WHO) on Friday described the spread of the disease in Iran as “very worrisome.” WHO noted that a woman in Lebanon may also have contracted the virus while visiting Iran.

WHO director Tedros Adhanom Ghebreyesus said the emergence of the virus in Iran was a sign that the “window of opportunity is narrowing” for controlling the epidemic.

“We need to act quickly before it closes completely. This outbreak could still go in any direction,” he warned.

WHO officials said Iran has the “basic capacity” to diagnose the coronavirus and keep it from spreading rapidly, which is not very reassuring. These officials said they were worried about the virus spreading from Iran into countries even less capable of detecting or controlling it. They were also troubled by the inability of Iranian doctors to determine exactly how the virus reached their country.

“The concern is that we’re seeing a very rapid increase in a matter of days,” WHO director of infectious hazard preparedness Sylvie Briand said.

Iraqi Airways announced on Thursday that it would suspend air travel to Iran until further notice due to the coronavirus outbreak.