Minnesota’s newest U.S. citizens softly muttered the opening of the Oath of Allegiance before U.S. Magistrate Judge David Schultz admonished them gently.

“This is one time it’s OK to use your outside voice,” he said.

During an uncommon ceremony at the Minnesota Children’s Museum, 23 youngsters from 12 countries officially became U.S. citizens. Adults must take the Oath of Allegiance at a naturalization ceremony, but foreign-born children who are adopted by U.S. citizens or whose immigrant parents naturalize become citizens automatically. If they are 14 or younger, a citizenship certificate arrives in the mail after parents request one.

But on occasion, United States Citizenship and Immigration Services holds ceremonies to make it an occasion to remember for children.

“Sometimes our office will say, ‘Hey, it’s State Fair time; let’s do a citizenship ceremony for kids at the grandstand,’ ” says Tim Counts, a local spokesman for the agency. “We do it, frankly, for fun — to make it more memorable, interesting and exciting for the children and their families.”

USCIS held a ceremony for 60 teens in the Mall of America rotunda back in June of 2014 as part of the mall’s annual Government on Display Exposition. This latest children’s ceremony happened after the newly reopened Children’s Museum reached out to the agency about hosting an event.

Of the 23 4- to 14-year-olds who took part in the Friday ceremony, eight were adopted, and the rest are children of immigrant parents who became citizens. They hail from Cameroon, Ecuador, Guatemala, Somalia, Uganda, Vietnam, Canada, Thailand, Korea, Ethiopia, South Africa and Kenya.

Schultz presided over the ceremony and urged the children to become engaged citizens and informed voters.

“Thank you for becoming citizens of our country,” he said. “All of you in one way or another have endured significant hardship to get to this country.”

Khalif Muhumed took the day off from his job as a truck driver in Willmar and drove to St. Paul with his 7-year-old son, Abdiraman, who sat in the front row in a button-down shirt, vest and slacks next to boys in shorts and sneakers.

Muhumed, a refugee from Somalia, remembered his own naturalization ceremony as bittersweet: He was thrilled to become a citizen but sad that his family hadn’t yet arrived from Africa to celebrate the event with him. So when he found out his son had been chosen for what was in a sense a do-over for his family, he said, “I was really excited.”

Amid last year’s contentious debate about immigration on the campaign trail, USCIS saw a marked uptick in citizenship applications. Nearly 1 million people applied to become citizens during the 2016 fiscal year, the largest number in the previous nine years, USCIS data shows. Children are not included in naturalization numbers.

Dianne Krizan, the museum’s president, touched on that immigration debate in remarks welcoming the new citizens.

“These are unusual times in our country, with so many disagreements on big issues including immigration,” she said. No matter what the children might have seen on TV, she said, “Without a doubt everyone here is absolutely welcome.”