Waukesha Christmas parade: Footage shows horrifying moment vehicle ploughs through crowd

Warning: This article contains graphic footage.

The horrifying moment an SUV plows into a US Christmas parade has been captured on camera.

Police say there have been several fatalities and at least 20 injured after the vehicle mowed down attendees in Waukesha, Wisconsin on Sunday (local time).

"The vehicle struck more than 20 individuals, some of the individuals were children and some fatalities as a result of this incident," Police Chief Dan Thompson said.

Bystander footage shows the SUV driving into marchers from behind, flinging their bodies aside.

Other footage taken in the aftermath shows a chaotic scene as witnesses scream. Several children were seen lying motionless on the ground.

The Archdiocese of Milwaukee confirmed several children who attend the Waukesha Catholic school were among the injured.

"Our prayers are with the people who have been injured and killed during the tragic incident in Waukesha," communication director Sandra Peterson said in a statement.

"Among the injured are one of our Catholic priests, as well as multiple parishioners and Waukesha Catholic schoolchildren. Please join us in prayer for all those involved, their families, and those who are traumatized from witnessing the horrible scene."

Police fired shots at the vehicle in an attempt to halt it, however the driver was able to escape. The vehicle was later found parked at a nearby address, and police say a person of interest has been taken into custody.

There is no word yet on what charges they might face, nor what their motive may have been.