Seventeen children are injured after their school bus collided with a mini-van and then spun out of control, crashing into a tree and stopping within a few centimeters of a house in Calgary.

One girl on board the bus when it crashed told CTV Calgary that neighbours in the area helped the kids get out through the back door as it filled with smoke and dust.

The children, all between grades 5 and 8, suffered only minor injuries like cuts and bruises, police told CTV.ca Thursday.

The drivers of both the bus and the mini-van were reportedly taken to hospital with serious injuries but are in stable condition. The children have all been released from hospital.

Calgary Police are investigating whether it was a mechanical or human error that caused the crash. First Student Canada, the company that owns the bus, launched its own investigation.

One boy on the bus told CTV Calgary that the children believe the bus driver tried to brake but couldn't stop.

"The brake didn't work and I knew that we were going to be a crash because I saw ice on the ground," said Shawn Lester, who is in grade 5.

Seventeen other children on board were taken to the hospital to meet their parents, but did not require treatment.

Police received a call about the crash, which happened in the northwest end of the city, at around 8:00 a.m. local time.

Six fire trucks and approximately 15 firefighters responded to the crash, according to a news release from the City of Calgary.

When emergency workers arrived on the scene the children were already being evacuated from the emergency exit of the bus.

"Chainsaws and other hand tools are being utilized to remove the bus from the grips of a large spruce tree that the unit ran into and rested on," stated the news release.

The owner of the house, Marilyn Gunn, said she heard a loud bang. She and a neighbour then helped the children out of the smashed-up bus, she said.

The Calgary Police traffic unit is investigating the accident.

With files from CTV's Kari Eyles and The Canadian Press