Three people were air transported to the hospital after a crash near Bala on Saturday afternoon.
Two air ambulances attended the incident on the B4391 at Pont Cwm Pydew between Bala and Llanrhaeadr ym Mochnant at 17.30.
Firefighters from Bala used cutting equipment to free three people who were trapped in two vehicles after the collision.
Three people were taken to the Royal Stoke University Hospital by air ambulance and another was taken to the Wrexham Maelor Hospital by ambulance.
Their condition is unknown.
The road was closed for almost three hours and just opened again after 8 pm.
In a previous incident, two cars were severely damaged after they collided with Trawsfynydd.
Emergency crews were warned about the incident on the A470 around 2.45 pm.
They found both vehicles off the road and on the edge of the road. A third vehicle suffered minor damage.
No one is supposed to be seriously hurt.
A passing motorist, who stopped to help, said that he believed that an animal might have run into the road, causing one of the vehicles to evade to avoid it.
"It is a very straight stretch and the driving conditions were good," he said.
The police closed the road for almost three hours.
The accident disrupted bus services that had to be diverted via Harlech and Barmouth.