SUDBURY -- Public health officials have declared a COVID-19 outbreak at Pius X11 Catholic School Monday after two more people tested positive for the disease, marking three cases connected to the school.

Sunday night, the Sudbury Catholic District School Board cancelled all classes at Pius XII following the first confirmed infection.

"Out of an abundance of caution and to ensure adequate supervision of students, the Sudbury Catholic District School Board is suspending all classes at Pius XII School on Monday, January 25, 2021 and all buses have been cancelled," the release said.

The first case at the school involves Grade 1.

Health officials now say the disease has spread to include Grade 2/3 and 6 and two bus routes, morning bus L106 and afternoon bus L104, but the investigation is ongoing.

"Individuals who are identified as close contacts of a case in a school setting will be directly contacted by Public Health Sudbury & Districts. Public Health will call these parents or guardians, as well as employees, to provide direction," said Public Health Sudbury & Districts in a news release Monday.

Parents are asked to monitor the school and board websites for additional information.

The school board has also announced that Marymount Elementary School has a confirmed case of COVID-19 resulting in two classes being dismissed until early February. Grade 7B and the native language class that is held Monday through Wednesday from 8 to 9:45 a.m. are both affected. While all students in these classes are being told to isolate, they should also be tested.

"If the test is negative but symptoms develop in subsequent days, retesting should be done," said the school board.

Health officials advise that families with young children have one caregiver isolate with them.

"It is understandable that this situation may make caregivers anxious and some will choose to keep their child at home as a precaution," the school board said in letters to families. "Please advise the school if you choose to do this so that we may make arrangements for continued learning when possible."

This comes after outbreaks were declared at two other Sudbury Catholic schools last week, St. Denis and St. David.

Despite the provincial stay-at-home orders that went into effect Jan. 14, most students in northern Ontario returned to in-class learning on Jan. 11 while their southern counterparts continued remote learning. The province cited lack of access to reliable internet along with relatively low school-related cases and transmission as its reasons for reopening schools during the lockdown. Schools in seven southern Ontario regions are reopening Monday, while those in the areas considered "hot spots" remain closed.

As of Friday morning, the Ontario government said there are seven schools with at least one reported COVID-19 case and two were closed.

In Sudbury, there are 67 active cases of the disease as of Sunday afternoon.