A man is fighting for life after being thrown from the back of a motorcycle as it collided with a car.
The serious crash happened on the A82, Balloch to Arden Road, at around 5.10pm on Monday.
Two men were travelling north on a black Suzuki motorcycle and as the biker slowed to turn right, it collided with a silver Volkswagen Gold Estate driving behind them.
Both men were thrown from the motorcycle onto the carriageway.
The 21-year-old passenger was taken by ambulance to the Queen Elizabeth University Hospital, where he remains in a critical condition.
The 23-year-old motorcyclist was taken to the Royal Alexandra Hospital in Paisley, from where he was later discharged, and the 46-year-old car driver was not injured.
Inspector Archie McGuire said: “We are appealing for anyone who was travelling along the A82 around the time of the incident, and is yet to speak to police, to please get in touch.
“It is imperative that we speak to all witnesses in order to gain a full view of what happened.
“Anyone with information is asked to contact the Divisional Road Policing Unit based at Dumbarton through 101, quoting incident number 2478 of Monday 31 August 2020.”