Three people have suffered minor injuries after a Brisbane tourist boat smashed into an unknown object, causing one passenger to fall through a floor into the lap of a woman sitting on a toilet below.

The accident happened when the Kookaburra Queen II paddle-wheeler was on the Brisbane River carrying about 50 passengers.

The impact smashed a hole into the upper deck of the Kookaburra Queen II, tearing a railing off.

Ambulance crews treated people for minor injuries at Eagle Street Pier, where the ship docked, with three taken to hospital.

One of the passengers, a woman in her 30s, fell through the floor of the smashed deck, landing on a woman in her 70s.

“The floor just parted and my wife went down and I fell on the deck,” the younger woman’s husband told Nine News.

Queensland Ambulance Service spokesman Warren Painting told the ABC two people in their 70s and a woman in her 30s suffered minor injuries.

“The commercial vessel was on the Brisbane River, struck an unknown object and the resulting jolt caused the injury of three passengers on board the vessel,” he said.

“The Bicycle Response Team was the first unit on scene and then there was also two other transport units and a supervisor.

“Conditions were pretty smooth today – it seemed to be a nice sunny day.”

Queensland Police are investigating the accident. Nine News reports that the skipper in charge of the Kookaburra Queen II’s at the time was in his first day on the job.

“We understand the person who was in charge of the boat at the time was relatively new and that will form part of the investigation as well,” Adam Muir from Queensland Police said.

-with agencies