The 51-year-old was detained on suspicion of murder and attempted murder after the auto crash outside a school in Loughton, Essex.
Officers are trying to discover a silver Ford KA thought to have actually been anxious within the scary hit-and-run.
One father, whose daughter was hit by the automobile, instructed Essex Dwell: 'A Ford KA mounted the pavement behind her.
Chief Superintendent Tracey Harman told reporters on Monday night: "We believe that the collision was deliberate and as such we have launched a murder investigation".
Police were called to the scene just after 3.20pm on Monday.
Essex and Hertfordshire Air Ambulance said it had treated "a number of patients", including two 15-year-old boys, a 13-year-old boy, a 16-year-old girl and a 53-year-old woman.
An Essex Police spokesman added: 'Officers from across the county are working diligently to identify the vehicle, and its driver, who failed to stop at the scene'.
The road has been closed in both directions and access is restricted from both sides of Debden Park High School, local media reported.
We are releasing the name of a man we want to speak to in connection with this investigation.
"We are investigating whether or not this incident may have been connected with another incident nearby".
"The school will be open on Tuesday with a number of counsellors on hand to support the community".
The cordon began metres from the entrance to Debden Park High School, near the junction of Jessel Drive. Please avoid the area where possible'. At least three of the teenagers were thought to be pupils at the school.
He said there was likely to be a "serious and prolonged investigation" into what happened. Our thoughts are with all those who have been affected'.