A number of people have been killed after a vehicle ploughed into crowds at a Christmas parade in a town in Wisconsin. A red sport SUV drove at speed into marchers in Waukesha about 20 miles west of Milwaukee on Sunday afternoon, causing “some fatalities” and injuring more than 20 people, the town’s police chief, Dan Thompson, told a media conference on Sunday night. Eleven adults and 12 children were taken to hospital, Thompson said, declining to give any more details about the number of casualties until families were notified. “The vehicle struck more than 20 individuals. Some of the individuals were children and there are some fatalities as a result of this incident,” Thompson told reporters. “We’re working with the families, that is our priority in this tragic incident.” The investigation was still “very fluid”, he added, and he did not know if the incident was terror-related. However, one person of interest was in custody and the vehicle involved had been recovered. Police investigate at the scene of the crash. Police investigate at the scene of the crash. Photograph: Mike De Sisti/AP In one video posted on social media, a red SUV appears to speed toward marchers, and in a second video police appear to open fire on the same vehicle as it crashes through street barriers. Eyewitnesses estimated the car was travelling at around 40mph when it struck the crowds. Another post appeared to show the car driving into a group of teenage girls dancing with white pompoms and wearing Santa hats. Another appeared to show the SUV hitting members of a marching band. Corey Montiho, a Waukesha school district board member, told the Milwaukee Journal Sentinel that his daughter’s dance team was hit by the SUV. “They were pom-poms and shoes and spilled hot chocolate everywhere. I had to go from one crumpled body to the other to find my daughter,” he said. “My wife and two daughters were almost hit. Please pray for everybody. Please pray.” The SUV drives through the Christmas parade in Waukesha, Wisconsin, on Sunday. The SUV drives through the Christmas parade in Waukesha, Wisconsin, on Sunday. Photograph: Jesus Ochoa via Spectee Michele Johnson, an eyewitness, wrote on the City of Waukesha Facebook page: “It was horrifying! The car drove past us and saw bodies flying. People screaming. It felt like feet from where our family was sitting.” Police had opened fire on the vehicle in order to try to stop it, Thompson said, quashing earlier reports that someone in the vehicle had opened fire on the crowds. A police advisory for residents to “shelter in place” was issued while police tried to trace the driver, Thompson said, and Carroll University in Waukesha went into lockdown. The threat to people was later declared over. Some of the injured were taken by police to hospital and others were taken by family members. Public schools would be closed on Monday and roads would remain closed for at least another 24 hours, authorities said. Waukesha police chief Dan Thompson talks to the media on Sunday night. Waukesha police chief Dan Thompson talks to the media on Sunday night. Photograph: Getty Images One witness said the driver hit the “Dancing Grannies” and at least one person flipped over the hood of the SUV, according to WISN-TV, an ABC affiliate. Photos and videos of Waukesha circulating on Twitter showed police cars and ambulances crowding a street decked out with Christmas lights in the aftermath of the incident. Writing on Facebook, another eyewitness, Lindsay Eckert added: “This happened right behind my dance team, the SUV drove past us going about 50-60mph. I saw people get hit and it was terrible. Everyone is devastated.” Angelito Tenorio, a local alderman who is running for Wisconsin state treasurer, said he had been at the parade with his family when he saw the red SUV approach the crowd. “We saw an SUV crossover, just put the pedal to the metal and just zooming full speed along the parade route, he told the Milwaukee Journal Sentinel. “We heard a loud bang, and just deafening cries and screams from people who are struck by the vehicle. “And then we saw people running away or stopping crying, and there, there are people on the ground who looked like they’d been hit by the vehicle.”