The force said it was believed the car was driven at the group following an altercation in the town centre.
Police said the driver abandoned the car and left the scene, adding counter-terrorism officers were not involved in its investigations and there was “no indication” of “any ongoing threat to the wider public”.
Det Ch Insp Ruby Burrow, who is leading the investigation, previously said: “We would ask that people do not speculate about the circumstances around the incident and respect the privacy of those involved.
“Our investigation remains ongoing and we are keeping an open mind while these extensive inquiries continue.”
A cordon was in place at Market Place, and the junctions from Gedling Road to Derby Street, Hallams Lane and Central Avenue, for most of Saturday.
Michael Payne, MP for Gedling, told the BBC at the scene: “We’re a tight-knit community in Arnold.
“My best wishes go to the individuals who’ve been hurt in the incident and I seriously hope that the said individual who’s got life-threatening injuries makes a recovery. My thoughts are with them and their family.”
Payne attended the scene alongside Gedling Borough Council leader John Clarke.
Clarke spoke of a need for barriers along the road, adding the borough council had previously called for the road to be blocked off to traffic.
Anyone with dashcam, CCTV, doorbell or mobile phone footage has been urged to contact police.