Police in Kansas City say an argument between several people that escalated led to a shooting that killed one and injured 22 others after a Super Bowl victory parade.
The deceased victim was identified as Lisa Lopez-Galvan, 43, a local DJ.
Police said the injured victims ranged in age from eight to 47 years old and that at least half are under 16.
Three suspects were taken into custody shortly after the shootings. Two of them are aged under 18.
"This appeared to be a dispute between several people that ended in gunfire," Kansas City Police Chief Stacey Graves told reporters on Thursday.
Chief Graves said firearms had been recovered, but did not give further details on the type of guns used in the shooting. She said no arrests had yet been made or charges laid and that the investigation is ongoing.
There was no link to terrorism, police said.
Ms Lopez-Galvan, who was identified as the one victim killed in Wednesday's violence, hosted Taste of Tejano, a Tex-Mex music show, on community radio station KKFI.
In a statement posted on Facebook, the station said: "This senseless act has taken a beautiful person from her family and this KC Community."
Nine injured children aged six to 15 were treated at the city's Children's Mercy Hospital. All are expected to recover from their wounds.
Kansas City Police have appealed to the public for further information about the shooting.
"We need to hear from anyone in the vicinity of the parade shooting today that directly witnessed the shooting incident, has any video of the shooting incident or who was a victim of the shooting who has not yet reported being shot," they said in a statement late on Wednesday.
A phone line and online tip page have been set up to collect information from the public.
More than 800 police officers were on patrol as hundreds of thousands turned out to watch a Super Bowl victory parade, which culminated in a rally outside Union Station in the middle of the Missouri city.
A stage was set up outside the station, which was decked in the red and gold colours of the Kansas City Chiefs, who won their second straight NFL championship on Sunday.
The rally had just ended at around 14:00 local time (20:00 GMT) when shots rang out to the west of the station, which remains closed on Thursday.
Videos posted online show members of the crowd tackling one of the alleged suspects on a street near the station.
One of the bystanders who stepped in, 46-year-old Paul Contreras, told NBC that he was at the parade with his three daughters.
"It was just a reaction. He was running the wrong way. There was another gentleman just screaming at the top of his lungs, 'This guy, tackle him'… I took him down," Mr Contreras said.
The videos showed a long-barrelled gun falling to the ground and a member of the public picking it up and placing on the ground away from the confrontation.
Chief Graves on Thursday praised the bystanders who stepped in and the emergency services who responded to the shooting.
"I'm angered about what occurred in our city yesterday, but I am also thankful for the response," she said.
Kansas City Fire Department Chief Ross Grundyson said medical personnel at the scene responded immediately despite some being just 40 feet (12 metres) from the shooting.
The parade violence is not unprecedented - several shootings at sporting celebrations have occurred across North America in recent years.
In 2021, two shootings left three people injured in Milwaukee after the local basketball team won their first NBA championship in 50 years.
In 2020 two people were killed in Los Angeles after the Dodgers won baseball's World Series.
Four people were shot and injured in Toronto in 2019 during a victory parade for the NBA Raptors championship win.
In a statement after the shooting, the Kansas City Chiefs organisation said it was "truly saddened" by the violence. It added that its players, coaches and staff - as well as their families - were accounted for and safe.
Travis Kelce, the star tight end of the team whose relationship with Taylor Swift became a cultural phenomenon, wrote on social media that he was "heartbroken over the tragedy that took place today".
