Police have closed the road in Humberstone Gate
Four people were injured when a car mounted a pavement and ploughed into a group of pedestrians.
A woman was seriously injured in the hit and run in Humberstone Gate, Leicester, shortly before 17:00 GMT, police said.
Eyewitnesses told the BBC they saw a car with a smashed windscreen being driven "erratically" after the crash.
Others said the car appeared to have been deliberately driven at the group of pedestrians.
Liam Mahoney said he had to move out of the way for "a screeching car" travelling the wrong way down Halford Street.
'Like ten pin bowling'
"It mounted the kerb at speed, went along Halford Street, collided with two vans, carried on at speed, and then turned along Granby Street and we heard a lot of commotion," he said.
Company director, Dr Beejay Bhatt, 36, said he saw a car come "barrelling down the road" and mount a pavement before sending a woman "flying".
He said a teenager was then launched into the door of a fast food outlet and "bounced" off, with emergency services arriving minutes later.
"It was pandemonium," he said.
Police have closed a number of roads near to where the accident happened
"Hundreds of people started crowding and the police had to put up this tape. It was like ten pin bowling."
Another eyewitness said: "I was on the side where the car drove over people. I was scared. I only just got out of the way.
"Everyone was just scurrying everywhere, like they didn't know what to do. There was quite a lot [of panic]."
A black car was found abandoned in nearby Bishop Street.
Ch Insp Dan Pedley, of Leicestershire Police, said: "There is considerable police activity in the area and roads are closed as a result of this incident which will understandably cause concern among residents and inconvenience to motorists.
"The investigation is in the early stages and officers are working to establish the exact circumstances surrounding this incident."
Police have said Humberstone Gate is currently closed, from its junction with Charles Street to its junction with Wharf Street South. Yeoman Street is also closed.
Diversions are in place and motorists have been advised to find alternative routes, the force said.
A car was cordoned off in Bishop Street
