Senior Sergeant Anthony Bond said officers were notified a bus had grazed the side of a building while turning a corner, resulting in a partially blocked road about 5pm on Saturday.
The bus had taken the corner too tightly when turning from St Andrew St into George St, and collided with the overhang of the Starbucks coffee shop.
Snr Sgt Bond said police believed a contributing factor to the crash was an unknown vehicle that they believe had stopped about 1-2 meters over the white line at the traffic lights on George St, which resulted in the bus being unable to complete the turn safely.
The vehicle had left the scene by the time police attended.
Police and Go Bus staff inspected the damage to both the bus and the store.
Several of the windows along the bus were damaged, said Snr Sgt Bond.
There were no reports of injury and the building was not badly damaged, he said.
Traffic was diverted while the bus could be freed about an hour later.
An investigation into the incident is ongoing and comes after another bus crashed into the veranda of a travel agent business in Moray Pl on September 21.
