The number of confirmed cases of COVID-19 in Massachusetts rose by more than 100 on Saturday, up to 525 from 413 on Friday, the state Department of Public Health said.

Of the reported cases, 51 patients have been hospitalized, while 215 have not.

Out of 3,031 patients tested for the novel coronavirus, 328 have been positive.

Middlesex County continues to have the highest concentration of COVID-19 cases, with 177. Suffolk County is the next highest with 108. Dukes and Nantucket have now reported one case.

Gov. Charlie Baker said in a press conference Saturday that the number of tests completed per day rose to 962 on Friday, up 85% from 520 on Wednesday.

Testing capacity has also grown at state and commercial labs, up to 1,144 on Friday from just under 700 on Wednesday.

“The capacity to test is going to continue to grow in signficant ways over the course of the next several weeks,” Baker said. “As the testing numbers go up, and as the criteria by which you can be tested expands, we certainly expect we will see an increase in the number of positive test cases as well.

Drive-thru testing began Saturday at the AFC Urgent Care in Waltham. To qualify for testing, patients need to be pre-screened via telemedicine.