TORONTO (Reuters) - A train driver has been seriously injured in a light-rail derailment in Calgary in western Canada, the public transit operator for the city said on Tuesday.

Calgary Transit spokesman Ron Collins did not specify the driver's injuries, but said the commuter train carried three passengers, none of whom were injured.

The cause of the incident was not immediately clear.

(Reporting by Ethan Lou in Toronto; Editing by Jeffrey Benkoe)