Ottawa has seen its single-deadliest day from COVID-19, with seven new fatalities reported since Thursday.

That brings the city's death toll to 21, Ottawa Public Health (OPH) said Friday. All seven of the new deaths are linked to retirement or long-term care homes, OPH said.

There are now 728 laboratory-confirmed cases in the city, an increase of 50 cases from the previous day.

According to OPH, wider testing could account in part for the rise in newly identified cases.

Ontario saw its largest single-day jump in confirmed cases Friday, with 564 new infections.

Eastern Ontario and western Quebec have more than 1,325 cases and 50 deaths, more than half of them in Leeds, Grenville and Lanark counties.

Nearly 400 people in the wider region are listed as recovered, but not all individual health units report this number.

Health officials have said there are likely thousands more undiagnosed cases in the region, partly due to limited testing.