Officers from North Wales Police were called to a single-vehicle collision involving a red Suzuki Swift on the A493 in Penmaenpool at 12.25am this morning (Wednesday, 24 August).
Officers attended, along with the Welsh Ambulance Service and North Wales Fire and Rescue Service.
A spokesperson for North Wales Police said: “Two passengers were taken to Ysbyty Gwynedd – one with serious injuries and a second is understood to have sustained significant, and potentially life-threatening injuries.”
Sergeant Emlyn Hughes of the Roads Policing Unit is appealing for witnesses.
He said: “Anybody who may have seen this red Suzuki Swift travelling along the A493 in Penmaenpool just prior to the collision is asked to contact us.
“I am also keen to speak to anybody who may have been in the area and who may have dash cam footage to get in touch.”
Anybody with information can contact the Roads Policing Unit via the live webchat or by calling 101, quoting reference number 22000624800.