Twenty-two people have been injured in a collision involving two coaches and a car on the A170 in North Yorkshire.
The accident happened at 1125 BST between Beadlam and Pickering.
North Yorkshire Police said two adults and two children were taken to hospital with minor injuries but later released.
Up to 100 people were on the coaches, which were taking youngsters and their parents or carers from Newcastle to the Flamingo Land theme park.
Many of those hurt suffered neck and back pain, the Yorkshire Ambulance Service said.
The two adults and two children were taken to Scarborough General Hospital or the Friarage Hospital in Northallerton.
A spokeswoman for the Yorkshire Ambulance Service said there were a "number of walking wounded" and several people had been checked over by a doctor at the scene but did not require hospital treatment.
It is believed one of the coaches crashed into the car travelling in front of it. The second coach is then thought to have hit the back of the first.
The four injured people were all travelling on one of the coaches, a Yorkshire Air Ambulance spokesman said.
A North Yorkshire Fire and Rescue Service spokeswoman said two fire appliances had attended.
Two air ambulances were called to the scene, along with a helicopter. They were later stood down.
North Yorkshire Police appealed for witnesses.