VANCOUVER – Some of Canada's top doctors are sounding the alarm about vaping as the number of serious illnesses linked to the habit creeps upward.

On Friday, health officials announced there are now three confirmed or probable cases of severe lung illness related to vaping across the country. The latest two come from New Brunswick, while the other was confirmed last month in Quebec.

Another case that was reported in Ontario is still classified as an "incident under investigation," and isn't confirmed to be vaping-related.

In response to the growing problem, the Council of Chief Medical Officers of Health released a renewed warning about vaping Friday that highlighted the potential dangers of using illegal products.

"We cannot stand by and watch a new generation of Canadians become dependent on nicotine or be exposed to products that could have significant negative consequences for their health," they wrote.

The doctors noted that investigations into severe pulmonary illness in the United States have suggested products containing THC, the main psychoactive compound in marijuana, are playing a role in the outbreak.

"The suspected cause is a chemical exposure, but the specific chemical or chemicals remain unknown at this time," they wrote.

"No single product or substance has been linked to all cases, and more information is needed to know whether a single product, substance, brand or method of use is responsible for the outbreak."

While the public awaits the findings of the investigations into vaping-related illnesses, the top doctors urged all Canadians to refrain from using e-cigarettes or vaping devices, legal or illegal. They said products that were purchased illegally or contain THC are of particular concern, however.

Anyone who vapes and then develops symptoms of ill health is urged to see a health care provider. Symptoms to watch out for include a cough, shortness of breath, chest pain or a general feeling that they are unwell.

The government has also set up a website where people can track the number of confirmed or probably cases of severe lung illness related to vaping across the country.