Fire Department Battalion Chief Michael Hopkins said eight to 10 people were injured but declined further comment, saying only that additional information will be released soon.
Police said in a news release that two people were detained. Fans were urged to exit the area as quickly as possible.
Lisa Money of Kansas City, Kansas, was trying to gather some confetti near the end of the parade when she heard somebody yell тАЬDown, down, everybody down!тАЭ
At first Money thought somebody might be joking until she saw the SWAT team jumping over the fence.
тАЬI canтАЩt believe it really happened. Who in their right mind would do something like this? This is supposed to be a day of celebration for everybody in the city and the surrounding area. and then youтАЩve got some idiot that wants to come along and do something like this,тАЭ she said.
Kevin Sanders, 53, of Lenexa, Kansas, said he heard what sounded like firecrackers and then people running. After that initial flurry, calm returned, and he didnтАЩt think much of it. But he said 10 minutes later, ambulances started showing up.
тАЬIt sucks that someone had to ruin the celebration, but we are in a big city,тАЭ Sanders said.
Lisa Augustine, spokesperson for ChildrenтАЩs Mercy Kansas City, said the hospital тАЬis receiving patients from the rally.тАЭ She didnтАЩt know how many or immediately offer any details about their injuries.
The University of Kansas Health System was treating one person wounded in the shooting, said Jill Jensen Chadwick, news director for the health system. She didnтАЩt know the personтАЩs condition.
тАЬWhen you have this many casualties, itтАЩs going to get spread out among a lot of hospitals so that you donтАЩt overwhelm single ER,тАЭ she said.
Missouri Gov. Mike Parson and the first lady were at the parade when shots were fired but are safe, Parson posted on X.
тАЬState law enforcement personnel are assisting local authorities in response efforts,тАЭ Parson posted. тАЬAs we wait to learn more, our hearts go out to the victims.тАЭ
Chiefs trainer Rick Burkholder said he was with coach Andy Reid and other coaches and staff members, and the team was on buses and returning to Arrowhead Stadium.
Areas that had been filled with crowds were empty after the shooting, with police and firefighters standing and talking behind an area restricted by yellow tape.
Throngs lined the route, with fans climbing trees and street poles, or standing on rooftops for a better view. Owner Clark Hunt was on one of those buses, holding the Lombardi Trophy. Former тАЬModern FamilyтАЭ star Eric Stonestreet was part of the mob.
Players rolled through the crowd on double-decker buses, DJs and drummers heralding their arrival.
тАЬWe are stacking up trophies,тАЭ linebacker Drue Tranquill said as he grabbed a reporterтАЩs mic during WednesdayтАЩs festivities to mark the ChiefsтАЩ come-from-behind, 25-22 overtime win over the San Francisco 49ers.
тАЬBest fans in the world,тАЭ exclaimed wide receiver Mecole Hardman, who caught the winning touchdown pass, as he walked along the route, with the players signing jerseys and at least one personтАЩs head.
Key on the minds of many fans is whether pop superstar Taylor Swift would join her boyfriend Travis Kelce for the parade and victory speeches. Swift has not commented. She has a show in Melbourne, Australia, on Friday night, the first of three scheduled concerts on her Eras Tour.
She was nowhere to be seen early in the parade. Instead, Kelce was joined by his mom, Donna Kelce, the superstar of NFL moms (her oldest son, Jason Kelce, is a center for the Philadelphia Eagles).
тАЬI missed last year. I said, тАШIтАЩm not missing this year,тАЩтАЭ said longtime fan Charles Smith Sr., who flew from his home in Sicklerville, New Jersey, for the parade.
Known by friends as Kansas City Smitty, the 52-year-old first became a Chiefs fan when Christian Okoye played fullback for the team starting in the late 1980s.
тАЬI got a history with this team,тАЭ he said, adding that he ran out of his home with a giant flag, screaming тАЬKansas City,” when the Chiefs clinched the victory in overtime.
The city and the team each chipped in around $1 million for the event commemorating Kelce, Patrick Mahomes and the Chiefs becoming the first team since Tom Brady and the New England Patriots two decades ago to defend their title.
After decades without a championship, the city is gaining experience with victory parades. Five seasons ago, the Chiefs defeated the 49ers for the teamтАЩs first Super Bowl championship in 50 years. That followed the Kansas City Royals winning the World Series in 2015, the cityтАЩs first baseball championship in 30 years. That year, fans abandoned their cars on the side of the highway so they could walk to the celebration.
Then, last year, the Chiefs defeated the Philadelphia Eagles 38-35 and prophetically vowed they would be back for more.