POLICE were called to a 'particularly nasty' multiple assault incident at a house in Torquay on Sunday night.
Detectives are still investigating the fight in which they say three people were injured, one seriously.
The assault involved numerous people in two rival groups and has been described by police as a suspected 'drug taxing' incident, which is when a group of drug users pursue others, which sometimes results in serious violence.
It is believed a mirror was smashed over one person's head in the fight.
Det Sgt Andy Turner said it was a 'particularly nasty' incident in a home in Warren Hill between 10pm and 11pm.
One of the occupants called police and an ambulance was requested. One casualty was taken to Torbay Hospital for treatment to head injuries. He was later released.
Det Sgt Turner said: "There were multiple attacks with punching and kicking. Three people were assaulted. Numerous people were involved in a fight."
Police believe there may be a drugs connection.
Three people were arrested on Monday and questioned in relation to the incident. A further person was arrested on Tuesday. Two more people were due to be arrested on Wednesday. Police said inquiries are ongoing.