EDMONTON -- Two more Edmonton schools were upgraded to outbreak status over the weekend, and a third to watch status. Alberta health services also reported possible transmission of COVID-19 on yellow buses at two schools.

The Edmonton Public School Board confirmed Monday that 27 cases of COVID-19 were found at its schools between Sept. 18 and 21.

Four more cases of COVID-19 at Vimy Ridge Academy on the weekend. An outbreak was declared at the school last week when a second case was detected, but as there are now six cases, the school has been upgraded to watch status. As a result of the cases, 169 students in various grades and 11 staff members are isolating at home for two weeks and monitoring symptoms.

Alberta's Chief Medical Officer of Health Dr. Deena Hinshaw noted in her coronavirus update on Monday that there had likely been in-school transmission at the school.

One case has been confirmed at Harry Ainlay School. One staff member and 47 students are isolating at home.

A new case was confirmed at Ross Sheppard School. This is the fourth case at the school. There are now 65 Grade 10 and 11 students and two staff members isolating at home.

One case has been confirmed at Northmount School. Four staff members and 29 students in a combined Grade 5/6 class are isolating at home.

One case has been confirmed at Victoria School. One staff member and 29 students from a Grade 3 class are isolating at home.

One case has been confirmed at York School. Three staff members and 19 students in a Grade 1 class are isolating at home.

One case has been confirmed at Kirkness School. Three staff members and 19 students from a combined Grade 5/6 class are isolating at home.

One case has been confirmed at Mayfield School. Three staff members and 23 students are isolating at home.

Two people are isolating at Delwood School after possibly coming into contact with COVID-19 while riding the yellow bus. 

Seven people from the Alberta School for the Deaf were asked to self-isolate on Sept. 20 after possibly being exposed to COVID-19 while riding the yellow bus.

One case has been confirmed at Aldergrove School. Three staff members and 16 students in a Grade 5 class are isolating at home.

One case has been confirmed at McLeod School. Two staff members and 22 students in a Grade 6 class are isolating at home.

One case has been confirmed at Dr. Donald Massey School. Four staff members and 37 Kindergarten and Grade 1 students are isolating at home.

One case has been confirmed at Beacon Heights School. Two staff members and 12 Kindergarten students are isolating at home.

Three more cases were confirmed at Highlands School. Nine staff members and 49 Grade 9 students are isolating at home. The school has now been upgraded to outbreak status, as there have been four cases reported so far.

Edmonton Catholic Schools identified eight more cases of COVID-19 between Sept. 18 and Sept. 21.

One case was identified at Austin O’Brien School on Sept. 18 and a second case was found on Sept. 20. As a result, 53 people are isolating at home. An outbreak has not been declared at the school.

One case has been confirmed at Bishop Savaryn School on Sept. 18.

One case has been confirmed at St. Joseph School on Sept. 18.

One case has been confirmed at Christ the King School on Sept. 19. There are 25 people isolating at home.

One case has been confirmed at St. Brendan School on Sept. 20. There are 87 people isolating at home.

One case has been confirmed at St. Matthew School on Sept. 20. There are 24 people isolating at home. 

An additional case has been confirmed at Holy Trinity School on Sept. 21.An outbreak has now been declared at this school. 

The province's interactive map of COVID-19 outbreaks in Alberta schools is available online.