These 33 Massachusetts communities have the highest risk of COVID-19

People in Lynn lined up at a coronavirus testing site on Tuesday.Suzanne Kreiter/Globe staff

A total of 33 Massachusetts cities and towns are at moderate or high risk for the coronavirus, including four north of Boston that are beset by heavy caseloads after months of closures and restrictions, Governor Charlie Baker said Tuesday.

The list of communities — less than one in 10 in the state — includes some of the most populous cities, often communities of color and lower-income areas.

Over the past two weeks, 29 communities, including Boston, Worcester, and Springfield, have averaged between four and eight cases per 100,000 people, a standard measure of the virus’s prevalence. Four other cities — Chelsea, Everett, Lynn, and Revere, densely settled communities with high proportions of essential workers — are at an even higher level of risk with more than eight cases per 100,000 people, according to the latest state figures.

“There is an extremely high level of COVID in your community,” said Secretary of Health and Human Services Marylou Sudders, addressing people in those cities. She urged them to “respect the virus” and take special care in following the now-familiar precautions: wearing masks, staying 6 feet apart, washing their hands, and staying home from work if they are ill.

Massachusetts is in the third phase of a staggered reopening process, but recent upticks in cases have sparked concerns among state officials and public health experts.

Baker said he and Lieutenant Governor Karyn Polito have reached out to leaders in the 33 communities with higher caseloads in the past couple of days “because we want to partner with them in whatever way makes the most sense to help them deal with the spread in their communities.”

The state could work with local officials to bolster testing, tracing, and isolation resources, he said at a news conference.

“We’re also implementing stepped-up enforcement measures, and we’ll also work with these communities on messaging and other communication strategies as we and they see fit,” Baker said.

Statewide, the death toll from confirmed cases of the virus rose by 10 to 8,529, public health officials reported. The number of confirmed cases climbed by 296, bringing the total to 112,969.

There were 96 new probable cases, bringing that total to 8,738. No new probable deaths were reported, so that total remained at 222.

State officials said 14,972 more people had been tested, bringing the total number tested to 1,337,606. The number of tests administered climbed to 1,759,976.

Baker warned the public to remain vigilant, asking residents “to recognize that this virus continues to affect, injure, and kill people every single day.”

“Regardless of where your community sits, COVID is not going away,” he said. “Your actions, no matter where you live or where you work, will determine in many respects how this virus spreads.”

Yet Baker noted that the vast majority of Massachusetts communities have held the virus below national benchmarks, a level of progress that suggested children in those towns could return to school. Residents of some communities with relatively fewer cases have argued that their schools should be reopened in the coming weeks.

Under the state’s color-coded system on a map released by Baker, green communities reported fewer than four cases per 100,000 people in the past two weeks, and white communities reported fewer than five cases in total. There are 318 communities coded green or white, with more than two-thirds in the white zone.

“We would certainly hope that, based on this data, if you’re in a green or white community, I can’t imagine a good reason not to go back, whether it’s full time or in some sort of a hybrid,” Baker said. “Because for all intents and purposes, you meet all the benchmarks that are being used across the country, across New England, to make decisions about whether it’s safe to go back to school.”

Cities and towns are finalizing their plans for fall after months of heated debates over the safety of allowing children to return to classrooms. State education officials have asked school leaders to prepare three possible approaches: a full-scale return to school, a mix of in-person and remote learning, or just remote learning.

The 29 communities determined to be at moderate risk are: Northampton, Holyoke, Chicopee, Springfield, Longmeadow, Granby, Belchertown, Charlton, Auburn, Worcester, Marlborough, Framingham, Maynard, Wrentham, Taunton, Fall River, Brockton, Randolph, Quincy, Hull, Boston, Winthrop, Malden, Saugus, Peabody, Salem, Middleton, Lawrence, and Georgetown.

Baker noted that he had recently announced a new enforcement and intervention team and said its mission “would make the most sense” in the moderate- and high-risk communities.

“The virus doesn’t care about boundaries. It certainly takes every opening any of us give it,” he said. “We’re making progress and have made progress in our fight, but we have seen the effects of too many people letting your guard down.”

In communities that have struggled to tamp down the virus, some officials said contact tracing showed that people had failed to abide by social distancing guidelines.

“What we see in terms of the recent increases in positive cases is really linked to large, personal, social gatherings — parties, house parties, barbecues, birthday parties, baby showers,” said Lynn Mayor Thomas M. McGee. “We’re not seeing connections to either the businesses or restaurants, or our nursing homes, or other things. . . . People are letting their guard down is what’s happening.”

McGee said city and state officials are discussing how to address the increase and are working to get the message out about social distancing and avoiding parties.

McGee said he spoke Tuesday with Revere Mayor Brian Arrigo and is in touch regularly with leaders in Chelsea and Revere about the outbreaks.

“We’re all four, the four communities, seeing the spikes, and I think we’re probably all seeing similar kinds of reasons for the uptick,” he said.

Everett Mayor Carlo DeMaria acknowledged his city has seen rising number of cases in recent weeks and pointed to an executive order he issued Monday requiring masks in public places.

“I’m hopeful this will decrease our numbers,” he said in a statement.

DeMaria said Everett is among the most densely populated communities in the country and may have a larger population than US Census data show, because many undocumented immigrants live there.

“We have a working class community and abundance of multigenerational living arrangements,” DeMaria said — situations that can make the virus harder to control.

Chelsea’s city manager, Thomas G. Ambrosino, said in an e-mail that the community had seen a modest increase in recent weeks “but nothing like April/May.”

On Tuesday the city had nine new cases, he said. “But, if we have nine per night, at a population of 40,000, that still puts us in the red at well over more than eight per 100,000,” he said.

Ambrosino said Chelsea had increased testing and messaging about wearing face masks, maintaining social distance, and avoiding large gatherings.

“Trying our best to keep people in the community diligent,” he said.

Peter Bailey-Wells of the Globe staff contributed to this report.