Ontario detected 293 new COVID-19 cases on Thursday, along with three new deaths, as the province moves to soon restrict private gatherings in three major cities in a bid to stem the virus' spread.

Ontario reported 315 cases of COVID-19 on Wednesday, 251 on Tuesday and 313 on Monday.

The numbers represented the highest daily count of infections since early June when counts briefly approached 400.

There are now 2,427 active cases of novel coronavirus infection in Ontario, up 111 from Wednesday after 179 people recovered from infection in the past 24 hours.

In late July there were less than 900 active cases of infection in the province.

"Locally, there are 85 new cases in Toronto with 63 in Peel and 39 in Ottawa. 70% of today’s new cases are in people under the age of 40," Health Minister Christine Elliott said on Twitter.

In response to rising numbers in Toronto, Ottawa and Peel, it is expected Ontario Premier Doug Ford will announce new lower limits for indoor and outdoor private gatherings in those three municipalities, after health officials said parties in private homes were driving the spread of the disease.

Elliott said provincial labs processed 35,000 test results.

The posivity rate on Thursday dropped to 0.84 per cent from above 1 per cent one day earlier.

More than 37,000 test specimens remained under investigation Thursday, possibly a product from the crush of demand for tests at assessment centres around the GTA.

Elsewhere in the GTA, Durham Region reported two new cases, Halton reported 12 new cases and York Region reported 37 new cases.

A count of data from local public health units on Thursday afternoon found at least 72 people are in hospital for treatment of COVID-19, higher than the province's official number of 53.

Of those, 21 are in intensive care and 12 are breathing with the help of a ventilator.