GPS showed the bus was travelling at 35km/h when it crashed.
A schoolboy had a cut forehead, which the manager believed was the worst injury.
All those hurt were taken to hospital. The driver was uninjured.
Elliot St residents said they heard a big noise and screaming passengers.
A fire chief at the scene said the passengers were mostly students, and he recognised Rosehill Intermediate and Rosehill College uniforms.
“We helped ambulance … there were a lot of walking wounded”, Papakura Fire Brigade senior station officer Brendon Lawson said.
A bus has smashed into a tree on Elliot St, Pahurehure. Neighbour Param Singh woke to a “big noise”.
By the time he dressed and went out five minutes later emergency services had arrived.
“Some of the people were screaming. So many neighbours came out, everyone was coming from their houses.”
The Auckland Transport bus was wedged against a tree, its windscreen completely smashed.
The bus It was extracted by a heavy duty tow truck.
“Oi, you can’t park there”, one motorist said, laughing, as they drove past the scene.
Eight people were injured when a school bus crashed into a tree in South Auckland. About a dozen firefighters from Papakura, Manurewa, Papatoetoe and a volunteer mobile support unit attended.
A St John spokesperson said eight people were injured.
Out of three people hospitalised, two were seriously injured and one was moderately injured.
“Two other patients self-transported to a local medical centre, in a moderate condition.
“The remaining three patients were assessed and treated at the scene.”
Three ambulances, a rapid response vehicle and manager went to the scene.
The police spokesperson said police were conducting a scene examination.
Eight people were injured when a school bus crashed into a tree in South Auckland. On social media, passing motorists reported seeing students on the roadside “looking shocked”.
Stacey van der Putten, Auckland Transport (AT) director public transport and active modes, said AT was working closely with emergency services and Ritchies to ensure a thorough investigation.
“This will have been a distressing incident for everybody onboard the bus and AT will be reaching out to passengers today to offer our support.”