CALGARY -- After Alberta Health admitted 12 cases of COVID-19 at an apartment building in the city of Calgary, additional precautions have been put in place.

Residents at Verve, located in East Village, are being told to follow strict protocol after an outbreak of coronavirus was discovered there last week.

In a letter obtained by CTV News, residents of the condo building were told to get tested, watch for any symptoms and self-isolate if instructed to do so by Alberta Heath Services (AHS).

In addition, they were instructed to wear a non-medical mask or homemade cloth mask to protect others while inside the building and outside it as well.

There are no details about what caused the outbreak in the building, but officials are looking into it.

"AHS is working closely with building management to ensure your safety," the letter reads. "We will continue to monitor the site closely for cases and to investigate the source of spread. We are investigating both direct person-to-person and surface spread as potential modes of transmission."

Alberta's chief medical officer of health, Dr. Deena Hinshaw, first announced the outbreak at the building during her update last Friday. She said the situation highlights a number of things when it comes to illness in shared accommodations.

"It seems that transmission is most likely to have happened through common high touch surfaces, emphasizing the need for cleaning and disinfection of these surfaces."

For further information about COVID-19 in Alberta, including how to access testing in your area, consult the AHS website.