St John Ambulance attended the incident and checked each pupil. None of the pupils had injuries which required them to be transported to hospital. Police and the Fire Service also attended.
"Please be assured that we will thoroughly investigate the cause of this incident to ensure the ongoing safety of our students," the statement said.
The bus was fully warranted and had undergone a routine check during the school holidays, according to the statement.
The school would contact parents who had a child on the bus.
Any parent concerned about their child, whether they were on the bus or not, was welcome to pick their child up from school.