The SUV that hit crowds at Wisconsin parade sped for more than 2 blocks, witnesses said, swerving and accelerating into dozens of people and killing 5

• Witnesses described seeing the car that drove into crowds at a Wisconsin parade on Sunday.
• The car crashed through a barrier and joined the main parade route where it sped up, they said.

Witness accounts out of Waukesha, Wisconsin painted a grim picture of how an SUV drove through the city's Christmas parade, leaving five people dead and at least 40 injured.

At 4.39 p.m. local time, a red Ford Escape smashed through a barricade and drove at speed into marchers there. CNN published video showing the car knocking the barriers over as it passed.

A graphic clip circulating online, showing a view of the SUV from an upper floor nearby, appears to show the car continuing at speed after running over several people.

A further video from the same location was shared by ABC affiliate WISN, which edited out graphic details.

It shows the moment the car made contact with a marching drummer just outside Divino Gelato Cafe, an ice cream parlor on Waukesha's West Main Street, before continuing further west.

A witness later referred to it passing People's Park, a cafe two blocks from Divino Gelato.

The parade had been on for around 40 minutes when one witness, Tom Hickey, said he heard honking from the red SUV behind him, he told The New York Times.

Hickey said he was walking behind a float at the time.

The driver appeared to be trying to make his way through the crowd, Hickey said, before turning onto the main parade route, revving the engine and heading off at speed. "That's when he turned really dangerous."

Jason Kellner, whose son was marching in the parade, told The Times that the car "started mowing people down" after turning. His son was unharmed, the paper reported.

One witness who was watching the parade from the side of the road, Tyler Kotlarek, told The Times that he believed the driver was trying to hit people.

"He was going from side to side, targeting people," he told the paper. "The car bombed through. He was flying through there going intentionally from left to right."

Police have given no official statement on whether they believe the incident was intentional. They said one person of interest had been detained.

Angela O'Boyle, who lives in a fifth-floor apartment on the street the parade passed by, told CNN that she saw the car "plow into" the band that was performing under her balcony at that moment.

"It hit at least two people right away and rolled over them," she told the outlet, saying it continued on past People's Park at the end of the block she was on. "It didn't stop."

One witness, an intern at the Milwaukee Journal Sentinel newspaper said the car "came barrelling down the middle of the parade."

Kaylee Staral estimated its speed at around 30 miles per hour. "I can't tell you if it's intentional or not, but they didn't stop the car," she said,