A car, found with the bodies of four missing teens inside, was on its roof and "partially submerged in water".
A hunt was launched for Jevon Hirst, Harvey Owen, Wilf Henderson and Hugo Morris after they failed to return home from an overnight trip to the Snowdonia area. North Wales Police said their bodies were recovered from a silver Ford Fiesta which appears to have left the road on the A4085 at Garreg, near Tremadog.
Superintendent Owain Llewelyn said: "At present, this appears to have been a tragic accident, and our thoughts are with the family and friends of the four young men at this very difficult time. This has been an extensive search involving a number of different agencies and volunteers, and this is sadly not the outcome that any of us would have wanted.
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"We would ask that the families be afforded the appropriate privacy and respect."
Mr Llewelyn later told reporters outside police headquarters in St Asaph: "Police officers attended and located a Ford Fiesta vehicle on its roof, partially submerged in water. Tragically, the bodies of four young males were recovered from within the vehicle.
"The families of the missing boys have been informed. Our thoughts are with them at this desperate time."
The force said inquiries were ongoing to establish the circumstances that led to the car leaving the road.
A Welsh Ambulance Service spokesman said: "We were called on Tuesday at approximately 10.08am to reports of an incident near the A4085 between Nantmor and Tan-Lan. We sent an operations manager, two emergency ambulances and two Cymru high acuity response units to the scene where we were supported by the emergency medical retrieval and transfer service in two Wales Air Ambulance charity helicopters."
A spokesman for Shrewsbury Colleges Group had said earlier: "The college's immediate thoughts are with the family and friends of the teenagers missing in North Wales. We can confirm that all four of the teenagers are students at Shrewsbury Colleges Group and are studying A-levels with the college."
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