The New Balance shoe-making factories in Skowhegan and Norridgewock closed Friday after an employee tested positive for COVID-19, marking the company’s first confirmed case in Maine.

It was the second time this summer the factories closed. The factories first closed for a day in June while an employee was awaiting a test which ultimately came back negative for COVID-19, the illness caused by the coronavirus.

New Balance is a Boston-based manufacturer of athletic footwear with factories in Maine that employ about 900 people at three sites.

“New Balance’s top priority is to maintain the health and safety of our associates, customers, and communities,” the company said in a statement Friday. “As soon as we were notified that an associate in our Norridgewock factory tested positive for COVID-19, our first confirmed case in Maine, we followed our comprehensive safety procedures. Our thoughts are with our colleague for a swift recovery.”

The factories were closed for a precautionary cleaning day.

In April, the company said some employees had to be furloughed amid the pandemic, but factories in Maine and Massachusetts had begin producing personal protective equipment, including as many as 100,000 masks per week.