A five-person smash near Llanberis saw a car burst into flames.
A Ford motor vehicle was destroyed following the two-vehicle collision on the A4244 near the tea rooms roundabout - between Llanberis and Bangor.
The incident was reported to emergency services shortly after 5pm on Saturday.
The driver of the Ford, together with a passenger were taken to Ysbyty Gwynedd.
The three occupants of the other vehicle were also taken to hospital.
A North Wales Fire and Rescue Service spokeswoman said:"There were five casualties involved who were taken to hospital.
"One appliance from Llanberis attended with a hosereel jet and oxygen."
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