Ontario's top doctor says the province will push back the return to school to next Wednesday as COVID-19 infections spike.

Classes were set to resume as early as Monday in much of the province, but critics called for clarity on the back-to-school plan in light of the recent spike in COVID-19 cases.

Dr. Kieran Moore says the extra time will give schools time to prepare for several changes, including providing N95 masks to staff in schools and daycares, deploying 3,000 HEPA filter units in addition to the 70,000 it has already rolled out.

He says the isolation period for those with COVID-19 will drop to five days from 10 days and publicly-funded PCR testing will be available only for high-risk individuals who are symptomatic or are at risk of severe illness.

He says the province would further restrict capacity in large indoor venues starting Friday with a hard cap of 1,000 spectators for larger venues.

Ontario is the latest province to announce changes to the start of school due to the fast-spreading Omicron variant. Some provinces have decided to prolong the winter break for some or all students, while others have opted to switch to virtual learning starting next week.

The news comes as the province has set several records for daily COVID-19 infections in quick succession, with the latest peak -- 13,807 new infections -- reported Thursday.