A motorbike racer who was involved a crash which left spectators injured has tweeted an apology, saying he is very upset, but there was nothing he could have done.
It was one of two crashes which happened at the Oliver's Mount road-race track near Scarborough yesterday on Sunday.
A total of 12 spectators were hurt in the two incidents.
A motorcyclist collided into spectators at around 10.40am, before a second rider crashed through a fence three hours later, hurting himself and others.
North Yorkshire Police say three of them were left with serious injuries, and were airlifted to hospital.
Two riders were treated at the scene.
Track bosses subsequently abandoned the rest of Sunday's programme.
In a statement, the circuit said:
"Today we have had two serious incidents involving a number of spectators. Our medical personnel, together with the marshals and officials of the club, local police, NHS, ambulance staff and helimeds have treated all the injured.
"In view of the seriousness of these incidents and our requirements to call on outside assistance to help with this treatment, we have reluctantly taken the advice of everyone concerned and have decided to cancel the rest of the meeting.
"We sincerely apologise to you all for taking this decision and hope you will understand our difficulties in this unprecedented situation.
"We wish you all a safe journey home."