Abdirahman Ahmed and a group of 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.

Dapper in a vest, slacks and dress shoes, the 7-year-old Abdirahman and 22 other youngsters from 12 countries officially became U.S. citizens in an uncommon ceremony at the Minnesota Children's Museum. Foreign-born children who are adopted by U.S. citizens or whose immigrant parents naturalize become citizens automatically; for most, a citizenship certificate arrives in the mail if parents request one. But rarely, United States Citizenship and Immigration Services (USCIS) holds ceremonies to make it an occasion to remember for children.

"We do it, frankly, for fun — to make it more memorable, interesting and exciting for the children and their families," said Tim Counts, a local spokesman for the agency.

In this case, the newly reopened Children's Museum reached out to USCIS with an offer to host such an event. The museum's president, Dianne Krizan, said in remarks welcoming the children that the timing had seemed especially opportune to celebrate the newcomers.

"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."

Amid last year's contentious immigration debate on the campaign trail and an ongoing spotlight on the issue, citizenship applications are on the rise. Nationally, nearly 1 million people applied to become citizens during the 2016 fiscal year, the largest number in the previous nine years, USCIS data shows.

The agency's St. Paul office, which also covers the Dakotas and western Wisconsin, saw about 14,200 applications last fiscal year, up 10 percent from 2015. This year, with almost 8,000 applications received in the first half, is on track to outpace last year's numbers. Children are not included in naturalization numbers.

USCIS last 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.

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, which featured all the trappings of adult naturalizations, including a medley of images of the White House, Lincoln Memorial, Statue of Liberty and other landmarks projected on a large flat-screen to rousing music. Schultz urged the children to become engaged citizens and informed voters.

"All of you in one way or another have endured significant hardship to get to this country," he said. "We thank you for the sacrifices you already made."

Khalif Muhumed, Abdirahman's dad, took the day off from his job as a truck driver in Willmar. They got up early, skipped breakfast and drove to St. Paul for the ceremony.

Muhumed, a refugee from Somalia, remembered his own 2011 naturalization ceremony at the University of Minnesota as bittersweet: He was thrilled to become a citizen but missed his wife and children terribly as other families shared the moment all around him. His family rejoined him several years later. So when he found out his son had been chosen for what was in a sense a ceremony do-over, he said, "I was really excited."

Napoleon Tayong, a father of three from Cameroon, acknowledged he balked at first at the prospect of driving 10 hours from Williston, N.D., where he works in a nursing home. Tayong came to the United States in 2009 after winning what's known as the green card lottery, an annual random drawing that grants 50,000 visas to natives of countries that do not send large numbers of immigrants here.

But his daughter, Mary, 13, in her favorite sleeveless flower-patterned dress, says she didn't mind the drive.

"I was really excited and really happy," said Mary, as her uncle held his 5-month-old son and wielded a hand-held video camera. "I get to be a part of community and a part of the United States."

Lt. Gov. Tina Smith and U.S. Rep. Betty McCollum also attended the event. McCollum urged the new citizens to study hard and perhaps one day consider running for Congress.

"You will be one of the few people on the planet who live in the best democracy in the world," she told Abdirahman and the other youngsters, tiny U.S. flags aflutter in their hands.

Mila Koumpilova • 612-673-4781