BALTIMORE (WJZ) — With COVID-19 cases rising, Baltimore City Health Commissioner Dr. Letitia Dzirasa on Tuesday said she strongly encourages residents and visitors wear masks indoors and at public gatherings, but the city is not yet reinstituting a mandate.

“I am strongly recommending that masks be worn indoors or in public settings regardless of vaccination status,” she said.

READ MORE: Maryland Weather: Mix Of Sun & Clouds

Over the last 28 days, cases have increased by 243%, she said.

In a statement posted to social media, Dzirasa noted many people are going on vacations and visiting friends and family, and organizers are planning outdoor activities like festivals, concerts and commencement ceremonies.

READ MORE: Traffic Advisory For US 50 East Before Bay Bridge

“Those plans may look totally different if we don’t get our shots and wear masks indoors as transmission levels increase,” she said.

Baltimore schools have been seeing outbreaks as well. Roland Park Elementary-Middle school had an outbreak after a weekend event.

About 30 people at the school were affected and 6th-grade classes had to go virtual.

MORE NEWS: Video Shows Squeegee Worker Assaulting A Driver At Busy Baltimore Intersection

“But we were just really thankful that even though it was an out-of-school event, we were able to get the word out quickly, be able to tell folks and to have the regular testing,” says Dr. Sonja Santelises, the CEO of Baltimore City Schools.

CBS Baltimore Staff