A man is in hospital in a critical condition after his ear was severed during a bloody road rage attack involving four men in Sydney's north west.
The 28-year-old was also stabbed multiple times and bashed in the head with a bottle, while his twin brother who was in the same car was taken to hospital with a leg injury.
The pair were travelling in a Toyota Hilux when they got into a fight with two other men, aged 23 and 19, in a Subaru WRX in the Parklea area on Wednesday evening.
Police said the argument culminated on the Stanhope Parkway near Warbler Street at The Ponds about 9pm.
Pictures show the passenger seat, dashboard and window of the Hilux drenched in blood. A large amount of blood can also be seen on grass outside of the vehicle.
The two men in the Subaru were also taken to hospital with non-life threatening injuries and are being interviewed by police.
Police said three of the four men have given different versions of the event and detectives have called for witnesses to the brawl, or the events leading up to it, to come forward.
A crime scene has been set up, and road closures are in place, on the Stanhope Parkway, near Conrad Road.
A resident on the street told Fairfax Radio the men were in a vicious brawl and she heard someone shouting "stop, stop, stop".
Another crime scene has been established nearby at Bather Streets in The Ponds where the Toyota was driven after the incident.
Residents reported hearing a tow truck remove the vehicle early in the morning and said they had not seen the car in the street before.
The silver Subaru was found about two kilometres away in Rochdale Circuit. The front of it was covered in blood and its windscreen was smashed.
The incident follows another road rage attack on Monday where a 73-year-old man was left with a fractured neck and bleeding in Strathfield.
Police said the elderly man was trying to get the registration details of a car, when a male passenger got out and punched him to the ground.
Security footage has been released of the man police believe responsible for the attack.
He was last seen running south past the Strathfield shops on the Hume Highway and is described as Caucasian with a noticeably receding hairline.
He was wearing beige-coloured trousers and a navy blue jacket with a collar at the time of the assault.
The 73-year-old was taken to Royal Prince Alfred Hospital in a critical condition. On Thursday, a hospital spokeswoman said his condition had improved to stable.