Toronto police are investigating after a city sightseeing bus and a police cruiser were involved in a head-on collision along Queen’s Quay.

Officers were called to the scene just before 3:30 p.m. on Tuesday at Queens Quay and York Street. At least one other vehicle was involved the crash.

Traffic Services Constable Clinton Stibbe says it’s believed the tour bus was travelling westbound on Queen’s Quay when it clipped a cube can heading eastbound. The bus then hit another car before colliding head-on with the police cruiser.

Seven people, including three officers, were transported to hospital with minor injuries.

Police are investigating a number of possible causes of the crash.