Police were called to Main Road, Watnall, at around 10.07pm on Friday evening after the victim, a 35-year-old man, was struck by a car.
The man remains in hospital where he is being treated for serious head injuries.
A 21-year-old man was also stabbed in the arm during the same incident, but his injuries are not life-threatening.
Detectives investigating what happened have now detained several suspects.
A 22-year-old man has been arrested on suspicion of attempted murder.
A 21-year-old man has been arrested on suspicion of causing grievous bodily harm with intent.
A 39-year-old man and a 24-year-old woman have also been held on suspicion of assisting an offender.
All four remain in police custody as investigations continue.
Detective Inspector Richard Guy, of Nottinghamshire Police, said: “This was a very serious incident that has left a man in hospital with very serious injuries.
“Our investigation is ongoing and officers are currently working through a wide range of evidence.
“We have already spoken to a considerable number of witnesses but believe other people may have vital information about what happened.
“Given the seriousness of what happened I would urge them to do so without delay by calling 101 and quoting incident 790 of 1 April 2022. Crimestoppers can also be contacted on 0800 555 111.”
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