Six people have been killed and 31 injured in a collision between a passenger train and a city bus at a crossing in Ottawa, Canada.

Wednesday's accident happened just outside a suburban train station in Barrhaven, in the south of the capital, during the morning rush hour, police said.

Photographs of the scene show the front end of the double-decker bus ripped off, and the train locomotive and one passenger car derailed.

Marc Messier, Ottawa fire-service spokesman, said rescuers found bodies and debris around the site of the impact.

All those killed were believed to have been travelling on the bus.

Eleven of those injured were said to be in a critical condition.

Pascal Lolgis, who witnessed the crash, said the bus appeared to drive through a lowered crossing barrier.

"He just didn't stop," Lolgis said.

Another witness, Mark Cogan, also said the rail barrier was down.

"[The bus] went through the guard rail and just hammered the train, and then it was just mayhem," Cogan said.

The crash is Canada's worst train accident since July, when an oil train derailed and exploded in Lac-Megantic, a town in Quebec, killing dozens of people.

Source: Agencies