The Middlesex-London Health Unit reported 12 new cases of the novel coronavirus on Saturday.
It is the highest daily increase of COVID-19 cases since May 10 when 13 new cases were reported.
There are now a total of 707 COVID-19 cases locally, with 621 recoveries and 57 deaths.
At least 29 cases are active in the region as of Saturday.
No new recoveries were reported Saturday, and the death toll has remained unchanged since June 12.
All 12 new cases are from the city of London, Ont., where there are now 655 confirmed cases.
Elsewhere, 26 cases have been reported in Strathroy-Caradoc, 12 in Middlesex Centre, six each in North Middlesex and Thames Centre, and one each in Lucan Biddulph and Southwest Middlesex.
Seven of the new cases are people under 19 years of age. One is in their 20s, one in their 30s, one in their 40s, one in their 50s, and one in their 70s.
Dr. Chris Mackie with the MLHU confirmed with 980 CFPL that the seven cases under 19 years of age are linked to three different households.
He says the youths caught the virus via household contact.
Mackie adds at least one new case of COVID-19 from Saturday above the age of 20 is from the same family as one of the youths.