A Scarborough school will be temporarily closed for one week after a COVID-19 outbreak was declared by Toronto Public Health.

Toronto District School Board confirmed Sunday evening that an outbreak at Mason Road Junior Public School has resulted in its closure from Sept. 28 to Oct. 2 as public health officials investigate.

Three staff members and one student tested positive for COVID-19, TDSB spokesperson Ryan Bird said in an interview with CP24.

"I don't have the exact symptoms or specific diagnoses of the people involved. All I know is that Toronto Public Health requested that we close it, and we obviously take our lead from the medical experts there. So that's why the decision has been made to close it and we've informed our school community," Bird said.

In a letter to parents, the school's principal and vice-principal said additional cleaning will be conducted in the school over the next week.

"I know news of an outbreak and school closure will, understandably, be worrisome for families. Please know that we are in constant contact with TPH and should they believe any additional communications or steps are required, we will let you know as soon as possible," the letter reads.

The school located in the area of Eglinton Avenue East and Markham Road is the second school in the city where an outbreak has been declared. The other is at Glen Park Public School.

During the city's COVID-19 briefing on Friday, Dr. Eileen de Villa said two students at the North York school contracted the disease.

In addition to the two cases, a teacher and 35 students from two cohorts were sent home to self-isolate for 14 days.

While Mason Road Junior Public School was asked to close, Glen Park remains open.

De Villa said an outbreak is declared when there are at least two confirmed cases of COVID-19 within a 14-day period, and at least one case was acquired in the school.

"The point of declaring an outbreak in any situation, whether it's a school or any other institution, is to actually allow for a swift response and to bring the resources to bear, to bring the infectious disease outbreak under control," de Villa said.

The city's medical officer of health also noted that she expects similar announcements in the future.

Bird also said Sunday's announcement while it was unfortunate, but it was not unexpected. He said that the board is taking all precautions to ensure that students and staff stay as safe as possible.

"With numbers increasing almost every day over recent weeks, we do know that this will happen," Bird said.

"But for us, what we're doing is we are making sure that we are taking all the precautions that we can whether that's mask-wearing, enhanced cleaning, screening prior to entering the school, physical distancing to the greatest extent possible."