The statement did not identify anyone arrested in connection with the operation or provide any additional details on the children, such as how long they had been missing or their ages.

The announcement also did not explicitly state whether any of the recovered children had been forced into commercial sex work.

But the Marshals said Operation Yellow Card, a reference to a violation in a soccer game, involves “proactive measures” to identify and locate vulnerable missing children at an “elevated risk” of trafficking.

“The upcoming FIFA World Cup is a monumental event for Massachusetts, but large-scale international gatherings historically bring a heightened risk of predatory exploitation targeting our communities’ most vulnerable youth,” said Dennis Matulewicz, acting US Marshal for Massachusetts, in the statement.

“Operation Yellow Card represents our unyielding commitment to intercepting these threats and securing endangered children before they can be pulled into networks of trafficking and abuse,” he said. “This operation’s early success in recovering 35 high-risk missing children is a direct result of the extraordinary, seamless cooperation” between state, local, and federal law enforcement.

Working together, Matulewicz said, “we are sending an unambiguous message to those who seek to harm children: we are aware, we are acting, and we will never stop looking for those in danger, nor will we relent in pursuing those who prey on them.”

His words were echoed in the statement by Suffolk District Attorney Kevin R. Hayden.

“The World Cup is bringing enormous benefits to our region, but it also brings the possibility of child exploitation,” Hayden said. “We and our partners will do everything in our power to prevent victimization and punish anyone who violates our laws.”

In recent weeks, officials and victim advocates have announced a series of public safety plans tied to the World Cup games here, with more than 2 million visitors expected to descend on the region.

Gillette Stadium in Foxborough — dubbed “Boston Stadium” during the World Cup — will host seven matches between Saturday and July 9, featuring teams from Haiti, Scotland, Iraq, Norway, England, Ghana, and France.

Ted Docks, FBI special agent in charge of the Boston division, has mentioned human trafficking at multiple recent press events related to World Cup Safety.

At one event that focused on trafficking, Docks was among more than a dozen members of law enforcement, activists for exploited people, and government officials who announced a public-awareness campaign and other efforts aimed at cracking down on trafficking for sex and labor.

They said they’re working especially with people in hotels, restaurants, and other hospitality or transit entities to spot and report trafficking, as well as asking the public to be aware and ready to call 911 or the national human-trafficking hotline, which is 1-888-373-7888.

The awareness campaign includes a billboard currently looming over busy Route 1 just south of Gillette: “Human trafficking” it says in large bold letters over close-ups of several eyes. “If you see something, say something.”

In the Marshals’ statement Thursday, Boston police Commissioner Michael Cox said his department has a unit devoted to fighting trafficking year-round.

“While this work is not new to us, we have increased the scope of our operations to manage the size of this summer’s events,” Cox said. “Our partnerships with the Massachusetts State Police, Suffolk County District Attorney’s Office, Federal Bureau of Investigations Boston Division, United State Marshal Service, the Suffolk County Children’s Advocacy Center and the Support to End Exploitation Now Program are all critical. We also want to thank the hotels in Boston for their partnership.”

The Marshals statement also included praise for the operation from the Plymouth and Essex district attorneys as well as State Police Colonel Geoffrey D. Noble.

Gillette Stadium sits within the jurisdiction of the Norfolk County district attorney’s office.

“Every missing and vulnerable young person deserves safety and security and to be given the opportunity to live free from the threat of exploitation,” Noble said in the statement, “Human traffickers prey on our most vulnerable, targeting those who are often isolated or in crisis.”

Noble said the “men and women of the Massachusetts State Police, along with our local and federal partners, have remained laser-focused on the mission of Operation Yellow Card, to locate missing children from around Massachusetts and provide them with the support and protection they deserve.”

Material from prior Globe stories was used in this report.

Travis Andersen can be reached at travis.andersen@globe.com.

If it feels harder than ever to buy a home in Massachusetts, you’re not imagining it.

But supporters of a new ballot proposal say it could help ease the state’s housing shortage and make homeownership more attainable.

It would change the way neighborhoods are built by allowing single-family homes on much smaller lots than currently permitted in many communities.

What the Legalize Starter Homes proposal would do

The group Legalize Starter Homes is pushing to get a question on the Massachusetts ballot that would expand where smaller homes can be built.

Under the proposal, a single-family home could be constructed on a lot if it meets a few basic requirements:

• At least 5,000 square feet of land
• 50 feet of frontage on a street
• Access to water and sewer infrastructure

That’s significantly smaller than what many towns currently require.

“It’s uncommon to have lot size requirements in the suburbs that are lower than 10,000 square feet,” said Andrew Mikula, chair of the Legalize Starter Homes Ballot Committee. “In a lot of places, it’s half an acre or more.”

Why supporters say smaller lots could help affordability

Advocates argue that relaxing lot size rules could make it easier to build more homes — especially entry-level housing.

Right now, the income needed to afford a typical starter home in the Boston area is out of reach for many buyers.

“The minimum income you need to buy an entry-level home, according to Boston Indicators, in the region is $162,000 a year,” Mikula said.

By allowing homes on smaller lots, supporters say construction costs could come down, opening the door for more buyers.

What this could look like in neighborhoods

The changes could have a noticeable impact in residential areas across Massachusetts.

Imagine a backyard, or even a space roughly the size of a basketball court, becoming the site of a new home.

For some homeowners, that idea is already appealing.

“My husband has mobility issues, and if we could build in our backyard, that would be amazing,” said Newton homeowner Beth Sagan. “We love the neighborhood. We don’t want to move.”

Local control would still remain

Even if the proposal passes, cities and towns wouldn’t lose all say over development.

Communities could still set rules around:

• Building height
• Parking requirements
• Spacing between homes

Supporters say the measure is designed to add flexibility, not override local planning entirely.

Part of a larger housing debate in Massachusetts

Housing experts say this proposal is just one piece of a much larger puzzle.

“Our housing systems are broken, not just individual policies,” said Jonathan Berk, board chair of Abundant Housing Massachusetts. “There is no one silver bullet solution to our housing crisis.”

The push comes as other housing options, like accessory dwelling units, or ADUs, are becoming more popular statewide.

Meanwhile, the Healey administration has set a goal of building 222,000 new homes between 2025 and 2035.

Supporters of the ballot initiative believe their plan could help meet that demand.

“We anticipate that this could do up to 20% of that goal,” Mikula said.

What happens next

The proposal is still working its way toward the ballot.

A decision on whether it qualifies could come as soon as early July 2026.

If it does make it on the ballot, Massachusetts voters will ultimately decide whether smaller lots — and more flexible housing options — should become the norm across the state.

First responders were at Ames Pond in Stoughton, Massachusetts, on Thursday, searching for a kayaker who’d been reported in distress.

Drivers were asked to avoid the area amid the search, which closed Highland Street between West and Canton streets.

The Kingston Fire & Emergency Management and first responders from other neighboring towns said they were helping in various ways.

More details about what happened weren’t immediately available.