Authorities in the northern US state of Wisconsin are seeking to establish the circumstances of a four-wheel drive vehicle that stormed a crowd gathered to participate in a Christmas parade in Waukesha, leaving 5 dead and 40 injured.

Waukesha Police - a suburb of Milwaukee, the capital of Wisconsin - said in a statement on its Facebook page - "We confirm that 5 people have been killed and 40 injured, but these numbers may change as we gather additional information," noting that a person was arrested pending investigation.

The accident - which authorities are still trying to gather information about - occurred in Waukesha while watching a traditional Christmas show that is held annually in Wisconsin (North).

According to witnesses and video footage, the car broke into the show from behind a school band.

School closures

"There was a Christmas parade in Waukesha when a red SUV drove over the barricades (...) heading for Main Street," Police Chief Dan Thompson told a news conference.

"The car hit more than 20 people, including children. There were injuries as a result of this incident," he added, noting that the Wakisha police found a suspicious car, and they are still investigating the matter.

The authorities also said that the police fired at the car in an attempt to stop it.

And it was decided not to open schools on Monday, while some streets will remain closed for the duration of the investigation, Thompson explained.

US President Joe Biden was informed of the incident, and the White House declared its sympathy "with those who were targeted in this terrible incident," according to a US presidential official.

"We have contacted local officials to offer our assistance if necessary," he added.

This incident came after a week of tension in the state with the acquittal of the American youth Kyle Rittenhouse of the charge of killing two men last year during riots and demonstrations protesting police violence in Kenosha, about 80 km from Waukesha.