DENVER (AP) — Boulder County is urging residents to take additional safety measures because of a rise in the number of COVID-19 cases.

In an announcement Friday, the county’s public health department said the number of new cases per 100,000 people had exceeded 200 in the last week, shifting the county from a “low” community COVID-19 level to “medium”, under federal guidelines. It suggested that people get tested before visiting people who are at high risk for severe disease and get fully vaccinated, including getting booster shots, among other measures.

The city of Boulder said it would return to holding virtual city council meetings because of the increase in cases, noting that council members and staff contracted COVID-19 after attending an in-person meeting May 3.

City councilors have been meeting in person since mid-April but the public has only been allowed to participate online. The public had been scheduled to be allowed back to meetings Tuesday.

Libraries, recreation centers and other government buildings will remain open, the city said, but city-sponsored public events will be held outdoors or conducted virtually for the foreseeable future. People who are not vaccinated or who are at high risk for severe disease are asked to wear a well-fitting, medical-grade mask in public buildings.