On the seventh anniversary of the Boston Marathon bombing, Boston Mayor Marty Walsh urged city residents on Wednesday to "stand together by standing apart," describing Boston as being at just the start of the surge in COVID-19 infections and asking people to remain vigilant and help one another.

Walsh, who planned to mark "One Boston Day" later in the afternoon by taking part in an interfaith prayer service livestreamed on the city's website, also announced that for the first time the city would be reporting deaths from COVID-19, in addition to cases, by race and ethnicity.

Of the 28,163 reported cases of COVID-19 in Massachusetts, 4,286 cases have been found in Boston, including 84 of the state's 957 deaths.

Walsh said of the cases in which race or ethnicity was known, 33 percent of those who have died in the city from COVID-19 were white, 29 percent Black, 15 percent Asian and Pacific Islander, 14 percent Latino and 9 percent identified as other.

Those numbers were higher for minority populations in Boston than the statewide data has shown. The Department of Public Health, which only recently started reporting demographic figures, reported Tuesday that 27 percent of deaths were white, 4 percent Black, 4 percent Hispanic, 2 percent Asian and 62 percent unknown.

The mayor said that compiling and sharing that data will help inform the hardest hit communities in the city and influence the city's decision-making about where to send resources.

"In Boston, we're putting equity at the core of our response," Walsh said.

Walsh said the city is currently putting together a webinar on the coronavirus for the Haitian and Creole community, and was working to make more testing available in Mattapan, East Boston, Dorchester and Hyde Park.

Starting this week, Walsh said, an expanded schedule for testing at Whittier Street Health Center in Roxbury will be available to all residents, and a testing site for first responders in East Boston will begin to serve the general neighborhood population by Friday as well.

By the weekend, Codman Square Health Center in Dorchester will also have expanded access to testing, and Brigham and Women's Hospital will expand services in its Hyde Park primary care site to offer screening and testing services for those impacted by the coronavirus and will deploy resources to other hard hit communities "in the weeks to come," the mayor said.

The city also announced that $1.7 million in new grants from the Boston Resiliency Fund had been awarded to more than six community health centers to support increased testing and other services, as well as family shelters like St. Francis House and Rise Massachusetts.

Walsh said that modeling he saw Tuesday showed that the city was as just the start of the surge, with the peak in cases not expected to arrive in the city until April 26 to April 28. That timeframe extends beyond the April 20 date that Gov. Charlie Baker has circled on the calendar for the end of the state's peak surge window.

Suffolk County, which includes the city of Boston, has been among the hardest hit regions of the state by the coronavirus, with its 5,872 cases trailing only the 6,254 cases recorded in Middlesex County.

According to data compiled by the New York Times, Suffolk County has the 19th highest number of cases by county in the country, and ranks 32nd among counties nationally for cases per 100,000 people.

"As the weather starts to get better and we're going to get better here in the next couple of weeks, it's getting warmer, we're asking people, please, no socializing. If you go for a walk keep your distance six feet from each other," Walsh said.

The city has already asked all residents to wear masks in public and recommended a 9 p.m. to 6 a.m. curfew.

"I'm hoping that we don't get to the point where we have to have a citywide shutdown but we have a responsibility each and every one of us to do what we can to protect ourselves, our neighbors, our families, our friends," Walsh said.

To mark "One Boston Day" commemorating the city's response to the marathon tragedy in 2013, Walsh said the city would be live streaming an interfaith prayer service on its website at 2 p.m., and the Old South Church would be ringing its bells at 2:49 p.m. to pause to remember the lives lost.

Walsh said the city would also make available online a list of "kindnesses" residents can engage in, including thanking first responders.

The Boston Police Department announced Tuesday that a 29-year veteran of the force Jose Fontanez had died of complications from COVID-19.

"The spirit behind One Boston Day is more important than ever," Walsh said. "This is a One Boston moment."