New Yorkers should wear a mask or face covering indoors at all times, even at work and in large spaces regardless if social distancing can be met, de Blasio said Monday morning.

Although the city’s key coronavirus indicators have looked favorable in recent weeks, Mayor de Blasio said infection rates in young adults is cause for concern. Infections are up in adults ages 20 to 29 even as other ages groups are experiencing mostly flat or declining rates of coronavirus infections.

Ten new coronavirus testing sites will open in the Bronx, Brooklyn and Queens, the mayor announced. Eight sites are already open and the last two will be open shortly, he said. Despite a growing access to free testing in the city, nationwide outbreaks have led to an overwhelming volume in testing and subsequent delay in lab results, de Blasio said.

Read more at NBC NEWS.