A school shooting in Iowa, where Republican nominating contests begin next week for the US presidential election, prompted prayers from among those wanting to be the party's candidate, but elicited no substantial policy proposals among the top contenders.

The incident saw a sixth-grade student killed and five people wounded after a 17-year-old opened fire on the first day of classes following the winter break, law enforcement officials said.

Florida Governor Ron DeSantis, who is locked in a close battle for second in Iowa with former UN ambassador Nikki Haley, said in an interview with NBC News and the Des Moines Register newspaper that authorities have a "responsibility to create safe environments" at school, but the federal government "is probably not going to be leading that effort."

He added in a later interview that if he were president, he would sign a bill abolishing the Bureau of Alcohol, Tobacco, Firearms and Explosives, which plays a major role regulating guns in America.

The candidates' reactions underscored how deeply gun ownership rights, which are enshrined in the Second Amendment to the US Constitution, are valued by Republican caucus-goers in conservative Iowa.

Most candidates ardently oppose any efforts to regulate guns and dismiss suggestions to that effect following mass shootings as an attempt to politicize tragedies.

Vivek Ramaswamy, who is polling fourth in Iowa, said in a statement he canceled a campaign event that was due to take place in Perry, where the school shooting happened, and changed it into "a prayer and conversation."

Haley offered her sympathies on X, the social media platform formerly known as Twitter.

"No parent, student, or teacher should have to wake up and face news about a school shooting," she wrote. "My heart aches for the victims of Perry, Iowa and the entire community."

Former President Donald Trump, the clear frontrunner who looks set to face President Biden in November's election, made no public comment about the incident.

Here are some other takeaways from the campaign trail:

Trump campaigns by proxy

Donald Trump's campaign on Wednesday night held one of the largest events of the Iowa presidential caucuses this January, and the Republican frontrunner was not even there.

Hundreds of the former president's supporters piled into a convention center in Sioux City, braving bitter temperatures and flurries to hear South Dakota Governor Kristi Noem speak on Trump's behalf.

Many attendees were emblazoned head-to-toe in Trump gear, while vendors outside sold merchandise from Trump T-shirts to stickers to keychains.

Trump is scheduled to host eight events in-person before the Jan. 15 caucus, a small number when compared to the other candidates. DeSantis held four events on Wednesday alone.

Instead, Trump is relying on his allies.

In addition to Noem, firebrand far-right Representative Marjorie Taylor Greene and Eric Trump, one of the president's sons, are hosting events in the eastern part of the state on Thursday. Ben Carson, Trump's former housing secretary, will host an event next week.

Trump has opted to attend many of the court proceedings related to his business dealings and his attempts to overturn his presidential loss to Biden. He is expected to appear at a federal appeals court hearing next week regarding the scope of his presidential immunity while in office.

If his voters care he is absent from some of his campaign events in Iowa, they are not letting it show. The Noem event was far larger than two DeSantis events in western Iowa on Wednesday, one of which was right down the road.

Dwayne Brown, a Trump supporter wearing a T-shirt with the former president's mugshot, praised Noem for keeping South Dakota largely open during the worst of the COVID-19 pandemic.

"Everything was open, except for the restrooms on the interstate," he said.

As the night wore down, an elderly woman stood on a chair in front of the stage and waved a "Caucus for Trump" sign while dancing to ABBA. After most attendees left, a pick-up truck flying a pair of Trump flags circled the empty parking lot.

Haley: One state will 'correct' another

Haley drew fire from rivals on Thursday after saying voters deciding on their party's candidate in New Hampshire, where polls put her second behind Trump, will "correct" the vote in Iowa, where she faces a much tougher contest.

"You know how to do this. You know Iowa starts it. You know that you correct it," Haley told an audience in New Hampshire on Wednesday evening, prompting laughter and applause.

Haley, who served as U.N. ambassador under Trump, and DeSantis are vying to become the clear alternative to Trump in a contest that is already down to six candidates.

After months of campaigning, Iowans will be the first to pick their preferred nominee in their caucuses, followed by New Hampshire's primary on Jan. 23.

DeSantis, who has staked a huge amount on a strong result in Iowa, seized on Haley's comments.

"I think it was incredibly disrespectful to Iowans to say somehow their votes need to be, quote, corrected. I think she's trying to provide an excuse for her not doing well," he said in an interview on KFAB radio.