Police say more than 20 people were hurt after a red car drove into a parade in Waukesha.
More than 20 people were injured after a car ploughed into a parade in Wisconsin, police have said.
Footage posted online shows a red sports utility vehicle (SUV) driving through a Christmas parade in the town of Waukesha, west of Milwaukee, at around 17:00 local time (23:00 GMT).
Onlookers screamed as people were knocked to the ground by the car.
Police chief Dan Thompson told reporters they had recovered a suspect vehicle.
He added that they had identified a person of interest but gave no further details. The injured were taken to hospital by ambulance, police and family members.
“Tonight was a traumatic situation for the City of Waukesha,” Mayor Shawn Reilly reportedly told a press conference.
One video shows the car crashing at high speed through street barriers. Another showed the vehicle driving into what looked like a group of musicians.
Local resident Angelito Tenorio told the Milwaukee Journal Sentinel newspaper he had just finished marching in the parade when the incident occurred.
“We saw an SUV… just put the pedal to the metal and just zooming full speed along the parade route. And then we heard a loud bang, and just deafening cries and screams from people who are who are struck by the vehicle,” he said.
Police officers ran down the street, telling people to take shelter in shops, local media reported.
A woman told Fox6 TV station the SUV hit a dance group of girls aged between nine and 15 years old.