VANCOUVER -- Two B.C. schools have temporarily closed because of COVID-19 exposures or outbreaks, the province's top doctor revealed in a briefing Monday.

Dr. Bonnie Henry said the two schools closed because of "exposures affecting larger numbers of staff and teachers."

One of the schools, Chilliwack's Mount Cheam Christian School, is in the Fraser Health region. Henry didn't officially declare an outbreak there, but said there were "exposures."

The other school closure was in the Interior Health region, at Kelowna's Ecole de l'Anse-au-sable, where an outbreak was declared last week. As of Friday, 11 people at the school had tested positive for COVID-19. 

"We knew of course this would be a possibility, especially in some of the smaller schools, where the potential of exposure impacts a larger proportion of the school population," Henry said.

"While the numbers of people with COVID are small, the requirement of those in contact to be in self-isolation has meant that the school can no longer safely operate."

Henry said the temporary closures will last for the duration of the disease's incubation period, which is typically thought to be two weeks.

"The schools are working with the families to ensure that educational opportunities continue remotely through this period," Henry said.

Henry also said the fact that the two schools are closed shows that their system "is working" and that officials are detecting cases early, adding that there's only been one school outbreak declared in B.C. so far.

Even so, health officials have faced some challenges.

"The investigation (in Kelowna) shows some challenge in understanding the transmission, so there may have been more than one person in that school who had COVID-19," Henry said. 

There have been more than 200 exposure events at B.C. public schools so far.

When it comes to schools, the term "outbreak" is used when multiple people have lab-confirmed COVID-19 infections and transmission is likely widespread within a school.

"Exposure" is a term used when a single person known to have coronavirus attended school while they were infectious. A "cluster" means two or more people were at school while infectious. These cases may or may not be linked to school-based transmission, according to public health officials.

With files from CTV News Vancouver's Kendra Mangione