Bridlewood School, St. Angela School and Lester B. Pearson High School in Calgary, as well as Raymond High School in Raymond and Lawrence Grassi Middle School in Canmore, have all reported in letters to parents that a case of COVID-19 has been diagnosed.
In a statement, Alberta Health Services said they were working directly with the schools to limit risk of spread.
"This includes assessing the [classroom] setting, and identifying and assessing the close contacts of the case," the statement reads. "Any individual considered exposed to this case will be contacted directly by Alberta Health Services.
"Infection prevention control measures (physical distancing, masking, hand hygiene, environmental cleaning) have also been reviewed with the school."
AHS said that a single case in a school population is not considered an outbreak, so no case-specific details will be shared.
All five facilities will remain open to in-person learning as the schools work closely with AHS to "ensure necessary measures are in place to protect all students."
The five facilities are the latest to report cases of COVID-19 since reopening last week. A case was also confirmed at Bowness High School earlier this week.
Calgary had 638 active COVID-19 cases as of Friday. Cases were also reported at Canyon Meadows School in Calgary and Meadow Ridge School in Okotoks before classes resumed last week.
Premier Jason Kenney said last week that his government has accepted that such infections are inevitable and don't warrant closing down all classrooms.
Similarly, Dr. Deena Hinshaw, the province's chief medical officer of health, said there was no perfect way for the province to relaunch — and no matter the levels of protection implemented, some cases will occur.
"We'll continue to watch, because we all continue to learn through COVID. We will take the learnings and put them into our models and our guidance moving forward," she said in an interview with CBC News last week.