BARRIE, ONT. -- Schools in Simcoe Muskoka will continue online learning after the ministry of education announced four more public health units in southern Ontario would be open for in-class learning Monday.

Education Minister Stephen Lecce said students would return to the classroom in the Ottawa, Eastern Ontario, Southwestern, and Middlesex-London public health units.

Lecce said the government's decision is based on advice from Ontario's chief medical officer of health. "The government agrees with the growing consensus in the medical community that returning students to in-person learning is essential to the wellbeing, development and mental health of children."

Schools within the Simcoe Muskoka health unit's geographical borders will remain closed despite Simcoe Muskoka's top doctor reporting a slight decline in cases week over week.

By Thursday, the region's health unit posted 149 new cases for the week, compared to 439 total cases for the week of Jan. 17.

Schools in the province's hotspots are set to return on Feb. 10, including York Region, Peel Region, Toronto, Hamilton, and Windsor-Essex, but the government has yet to confirm that date.

Northern Ontario schools reopened on Jan. 11, as COVID-19 cases remain low in those areas.

The Simcoe Muskoka Catholic District School Board stated in an email to CTV News Wednesday that they had no clear date for returning to in-person learning.

"The Ministry of Education has indicated that they will connect with us in early February to confirm when our return to in-class learning will be. The decision really is dependent on the advice of public health, and we will return based on direction from the ministry," the board noted.

Students returned to in-person learning at several school boards Monday, including Bruce-Grey Catholic District School Board, Bluewater District School Board, Kawartha Pine Ridge District School Board, and Trillium Lakelands District School Board, except for those schools located in Simcoe Muskoka.

The province announced changes for back to school, including enhanced screening, asymptomatic testing and students from Grades 1 and up would be required to wear masks if returning to in-person learning.

Despite some schools getting the green light to reopen, the province remains in a state of emergency, including the stay-at-home order, after the government officially extended both for an additional 14 days on Monday.

The province-wide lockdown was issued on Dec. 26 and, if it's not extended, will expire on Feb. 11.

Ontario's chief medical officer had said previously that daily provincial COVID-19 cases would need to consistently fall under 1,000 before the tightened measures would ease.