Four schoolchildren are in hospital after a school bus ploughed into a crowd of youngsters.
Two were said to be "poorly but stable" and two others "comfortable" after a 33-seat Mercedes bus carrying more than 20 children left the road outside English Martyrs School in Hartlepool.
Shocked young eyewitnesses described how the minibus appeared to swerve to avoid a child who had run into the road. It then ploughed into a fence and a tree where a crowd of children was gathered.
Many of the injured are thought to have been from among the children on the street and not on the bus. Details of exactly what happened are still sketchy but youngsters who witnessed the crash said pupils were running around covered in blood.
Hospitals in the area confirmed 23 people had been taken in for treatment, but only four were detained. The most seriously injured were two 12-year-old boys who were airlifted by an air ambulance and a police helicopter to James Cook University Hospital, in Middlesbrough.
A hospital spokeswoman said their condition was "poorly but stable". Police said both were pupils at English Martyrs School. Two other children detained at the University Hospital of North Tees, in Stockton, are said to be "comfortable". All the other casualties, who were taken to the hospitals in Stockton and Hartlepool, were later released after treatment.
The incident is now being investigated by Cleveland Police and the bus is still embedded in the fence outside English Martyrs School.
Sergeant Paul Dee, of Cleveland Police, said: "I am led to believe that the vast majority of the casualties were pedestrians. The driver of the minibus has been spoken to and has given an account of what happened."
English Martyrs School headteacher Joe Hughes said everyone at the school had been left shocked by the crash. He said: "Everyone is very concerned and very worried and our thoughts are with the students in hospital. We will be praying all through the night that the outcome is the best possible one."
English Martyrs School, a voluntary aided Catholic school, caters for 1,540 children between the ages of 11 and 18 and it is thought that the children on board the minibus were aged around 12 and 13. Mr Hughes said that he understood there were about 26 children on board the bus and he understood also that it was fitted with seatbelts.
