CALGARY -- Grade 10 students at Western Canada High School are being moved to online learning for the next two weeks due to "operational capacity concerns."

A letter to parents from school principal Carma Cornea says students are scheduled to return to in-class learning on April 27.

"This will help to ensure we are able to provide focused instructional support for all students and ensure that there are adequate staff in place to support the safety and learning of all students.

Grade 11 and 12 students will continue with in-class learning.

"We are working closely with AHS to ensure necessary measures continue to be in place to protect all staff and students," reads the letter.

Later Tuesday, CBE confirmed that Grade 10 and Grade 12 students at Joane Cardinal Schubert High School are also moving online temporarily, through April 21.

According to CBE, a total of nine schools have one or more grade cohorts learning online, including Western Canada and Joane Cardinal Schubert.

There are 453 schools — a total of 19 per cent — experiencing outbreaks and there has been 2,653 cases linked to schools since Jan. 11.

Alberta's Chief Medical Officer of Health Dr. Deena Hinshaw says the province is seeing a "sharp rise" in the number of cases among school-aged children, however transmissions are linked to social activities outside of schools, rather than classrooms.