Boston Mayor Marty Walsh warned against large gatherings and crowds at beaches on Thursday, saying they could lead to a coronavirus spike like those now being seen elsewhere in the country.
"It looks like we're headed for another hot weekend," he said. "Many people are going to be outdoors. But we need to continue to be smart and diligent about it. We can't afford to see more crowded beaches like we did. If this keeps happening, we'll get outbreaks and see more restrictions being imposed."
Photos from M Street Beach in South Boston last weekend showed large groups of people gathered with little to no social distancing.
"We can't afford to see house parties," the mayor added, referencing a recent party with between 30 to 50 people in Chatham that led to a cluster of at least 10 COVID-19 cases. "Let's all stay mindful this weekend as we continue to move forward here."
Walsh was also asked if he is concerned that the return of college students in the fall from areas of the U.S. with higher coronavirus numbers could lead to another surge in Boston.
"Seeing what's happening around the country is concerning me," he said. "Many of our college students come to Boston for school. The live here, they work here. They're coming from high risk areas. We're going to monitor this very closely.'
In-depth news coverage of the Greater Boston Area.
"It's a double-edged sword," Walsh added. "I'd love to see the college students come back, but I'm also concerned about if we don't have a really good screening process, what does that mean for our numbers down the road?"
Get Boston local news, weather forecasts, lifestyle and entertainment stories to your inbox. Sign up for NBC Boston’s newsletters.
He said those returning college students should not be looking to hold parties, but he hopes he won't have to use police to enforce that edict.
"College students that come here in the fall, we're going to ask them to police themselves," Walsh said. "People need to be careful. I would not advise college students to be having parties. I think colleges will be pretty strict with their regulations, but if I have to, I'd use police, yes."
As of Thursday, Boston had reported 13,924 cases of COVID-19, including 723 deaths.
The mayor was also asked Thursday for his thoughts on the preliminary draft of Boston's fall school plans
The conversation about reopening options for Boston Public Schools kicked off during a school committee meeting Wednesday night, during which the superintendent presented preliminary plans for the fall. The virtual meeting drew so many people that the online capacity needed to be increased.
A hybrid option, known as the "hopscotch model," received the most attention. The measure involves separating students into two groups, with each group returning to the classroom two days a week, and closing the buildings one day a week for deep cleaning.
Walsh urged patience, saying many things could still change before the scheduled opening of Boston schools on Sept. 10.
"My goal today, my intention today on July 23rd would be to have school open September 10th," he said. "That would be my hope. But one week from today I could be standing at the podium saying we've had a big increase this last week. This is going to be an ongoing, fluid situation."