Sussex Police have been granted extra time to question three people who were arrested after a man was attacked and then run over in Brighton.
The 33-year-old victim remains in hospital after the incident in The Causeway on Saturday.
Detectives have been given an extra 36 hours to question two women, aged 26 and 29, and an extra 12 hours to question a 55-year-old man.
They were all arrested on suspicion of attempted murder.
The detained man was treated at hospital before being released into police custody on Sunday.
Det Ch Insp Nick May said: "This extra time will allow us to question the suspects further so that we can build up a full picture of what happened.
"The 33-year-old victim remains in hospital in a very serious condition and we have been unable to gain an account of events from him.
"This appears to be a case in which a personal dispute between two groups of people has got out of hand.
"We believe these people are all known to each other and no other members of the public were involved at any point."
Forensic searches have been carried out in The Causeway.
Officers have said they want to speak to anyone who saw a green 4x4 being driven along The Causeway.
Police have urged anyone who has information or who saw the incident, which happened at about 1530 BST, to contact the force or Crimestoppers.