A man has been arrested on suspicion of attempted murder, following a collision involving three mopeds and a car.
The moped riders, two men aged 20 and 18 and a 16-year-old boy, were taken to hospital after Tuesday's incident in Damson Parkway, Solihull.
One line of inquiry was whether a Mercedes car was deliberately driven at the mopeds after an earlier road rage incident, police said.
The arrested man, aged 70, handed himself into police later that day.
He has since been released under investigation, the West Midlands force said.
The two young men and the boy were taken to hospital with injuries that are not life-threatening or changing.
The driver of the Mercedes involved fled the scene, police said.
Sgt Kelly Mills, from Force CID, said: "We're following several lines of enquiry and particularly want to hear from anyone who was in and around Coventry Road and Damson Parkway and may have dash cam footage."
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