TORONTO -- Winter weather in Ontario disrupted the students' anticipated return to in-class learning in some COVID-19 hot spots Tuesday, as the education minister reassured parents that new safety measures were sufficient to controlling COVID-19 spread in schools.

Schools boards in Peel and York regions closed schools and cancelled bus services due to heavy snowfall, though classes continued virtually.

In Toronto, classes were held in-person in Catholic and public school boards, though no transportation was provided.

In-person lessons were slated to restart in those three regions after a stretch of online learning that began in January as part of a provincial lockdown, which along with a stay-at-home order helped bring the number of new COVID-19 cases to below 1,000 per day.

But modelling presented last week said new, more infectious variants of the virus were poised to become prevalent and would

cause cases to rise this month.

Education Minister Stephen Lecce said Tuesday that new measures -- including expansion of an asymptomatic testing initiative, stricter masking rules for younger students and a COVID-19 screening form -- should help keep cases low in the province's schools.

But he also called on school communities -- in particular, high school students -- to avoid mingling outside of schools to prevent the more infectious variants from spreading.

"We know we can keep schools open and safe," Lecce said in an interview. "But it does require ... the partnership of all of us because given that historically higher rate of positivity amongst high school kids, it's going to require a real collective commitment to not congregate."

He said the province is asking students and staff to "respect the cohorts" of student groups and not gather together outside their classes.

The Education Ministry reported that 50,000 asymptomatic tests are available for use on a voluntary basis across public health units this week, including at 40 schools in Toronto. Their deployment falls to local public health units, and an exact figure on tests deployed to date wasn't yet available on Tuesday.

The Greater Toronto Area hot spots are also poised to exit a stay-at-home order and return to the province's colour-coded public health restriction framework on Feb. 22 -- and the timing has given rise to concern from local health officials.

Dr. Lawrence Loh, medical officer of health for Peel Region, has said he supports reopening schools but further economic reopening is risky.

"Anything beyond schools at this point in time, I really think we need to take a very close look at," Loh said in an interview.

He said some other sectors may not have the same safety precautions in place, and the new variants may be spreading in different ways, meaning the current provincial framework might not be best suited to controlling the pandemic now.

"We know that as the variants are here and being detected in alarming frequency, we really do need to also reconsider the whole context and picture has changed as well," he said.

Lecce pointed Tuesday to the "emergency brake" measure introduced in the government's reopening plan that will allow the province to move regions quickly back into lockdown if cases rise.

He said that part of the reasoning behind the Progressive Conservative government's decision to defer March break until April was based on modelling that suggested a rise in variant cases during the break when people might gather in groups.

Despite the risks, Alicia Glenn, said she's ready for her two children to head back to class.

"We feel that for their mental health, their social development and their overall education, they really need to go back (to school)," the Toronto mother said.

This report by The Canadian Press was first published Feb. 16, 2021.

- with files from Denise Paglinawan