Entire Grade 12 class at Calgary high school told to stay home for 2 weeks due to COVID-19

All Grade 12 students at John Diefenbaker High School in northwest Calgary have been told to stay home and take online classes for two weeksafter "a number of positive cases" of COVID-19 were identified, the school says.

"Many Grade 12 students and associated staff members have been identified as a close contact of one of these cases and will be required to isolate at home for up to 14 days," reads a letter to parents sent by the school, located at6620 4th St.N.W.

"Due to staffing capacity issues,the decision has been made to move all Grade 12 students to online classes from Thursday, Nov. 12, until Friday, Nov. 20."

In-person classes will continue for those in Grades 10 and 11.

The school says it is working closely with Alberta Health Servicesto "ensure necessary measures continue to be in place to protect all staff and students," the letter says.

The notice comes as the province grapples with surging case counts and has stopped widespread contact tracing because it was unable to keep up.

Alberta reported 672 new cases of COVID-19 on Wednesday afternoon, but did not release the number of active cases across the province, or the regional breakdown.

On Tuesday, it was reported that there were3,434 cases in the Calgary Zone.

A group of more than 430Alberta physicians and three major health-care unions are sendinga letter to Premier Jason KenneyThursdayendorsing the idea of a "circuit-breaker" lockdown as cases of COVID-19 continue to surge in the province.

Sources have told CBC News that the government will introduce new measures on Thursday afternoon, but that those measures are anticipated to be modest and targeted.

KenneyandAlberta's chief medical officer of health, Dr. Deena Hinshaw, have scheduled a news conference for 3:30 p.m. MT and CBC News will carry it live on the website and Facebook.