Alton Towers' new £18m Smiler rollercoaster was forced to shut down after some of the ride’s wheels fell off and hit four people in the front carriage.

A spokesperson for the park said that some “small guide wheels” had come off The Smiler as it was being pulled up an incline.

The spokesperson said the ride was able to complete its circuit and no evacuation was necessary. The plastic guide wheels were flicked onto a teenager and three adults on the front row of the train, the remaining guide wheels were caught by the safety netting.

The 14-loop rollercoaster has had its share of problems since opening. The ride shut for four days in 21 July after a piece fell off the track and 48 people had to be rescued. In August the ride closed for five days due to “technical issues”.

The injured people in the latest incident were treated on site by park staff and did not need treatment by the ambulance service. The park has started an investigation to decide when the ride could reopen, but at present nothing has been confirmed.