VANCOUVER -- A "small group of students" from a private school in West Vancouver were potentially exposed to COVID-19 during a recent field trip, according to a letter sent out to parents.

Mulgrave School said all students and staff who are considered to be at risk have already been told to self-isolate for two weeks. Affected students will be learning remotely during that time, with help from quarantined teachers.

The exposure involves Grade 9 students and "occurred while they were away from campus for an off-site day camp experience," according to the letter that parents received Monday.

Administrators said Vancouver Coastal Health alerted them about the exposure on Sunday night, and that the health authority did not recommend any additional precautionary measures inside the school.

"Camp activities took place outdoors within learning groups and involved physical distancing, which helped limit the risk to members of the Mulgrave community," reads the letter, which was written by head of school John Wray.

"Because the exposure occurred off-site, there has been no recommendation to do anything beyond the usual thorough cleaning of the school that takes place throughout the day, every evening, and over the weekends"

The school asked parents to "remain calm and empathetic," and encourage the same in their children.

"We understand, of course, that parents will naturally be concerned by this situation, but please be reassured that Mulgrave will continue to be vigilant in the implementation of the protocols and procedures that we have in place so that children can continue to attend school as safely as possible," Wray wrote.

News of the exposure spread on Tuesday, as teachers in public schools across B.C. returned to classrooms for the first time to prepare for the fall semester.

Many parents in the province have expressed concerns about sending their children back into classrooms. A recent Research Co. poll found 39 per cent of residents disagree with the decision to allow in-class learning.