The incident happened around 12.30pm yesterday (12 August) near The Bandstand restaurant and involved a blue community transport bus.
Two passengers on board were injured and taken to hospital.
An 81-year-old woman had minor injuries and was later discharged, and an 86-year-old woman sustained serious injuries and remains in hospital.
Were you in the area at the time? Perhaps you saw the blue bus in the run-up to the incident or maybe you have dash-cam footage?
Anyone with information can contact us online or by calling 101 quoting 44210320816. Alternatively, you can contact the Crimestoppers charity anonymously on 0800 555 111.