PEMBROKE, Ont. - An eastern Ontario high school has been ordered to close after three staff members tested positive for COVID-19 since last Friday.

The Renfrew County District School Board posted a notice on social media Wednesday saying the local public health unit had ordered the immediate closure of Fellowes High School in Pembroke, Ont.

The notice says the third COVID-19 case was detected on Wednesday and was linked to two previously announced cases, all among staff members at the school located northwest of Ottawa.

The Renfrew County and District Health Unit declared the outbreak on Tuesday after the second case was detected.

The school board says the school will remain closed until public health officials approve its reopening.

The board says people who aren't contacted by public health are considered to be at a low risk of exposure.