Los Angeles fire officials say a collision involving a commuter train and two cars apparently began with a street crash that hurled one or both of the vehicles into the train's path.

Fire Department spokesman Brian Humphrey says four people in the cars have been injured, two of them critically.

Firefighters have been examining at least six people on the train for possible injuries.

Humphrey says witnesses to the 7 a.m. Wednesday incident told firefighters that after the two-car collision occurred, one or both of them were hit by the train.