Officials in Chicago say at least two women have been killed and scores of other passengers injured in a train derailment.

Authorities say they do not know what caused the five-car commuter train to go off the tracks Saturday. At least 80 people were injured, some seriously.

Almost 200 people were on the train at the time of the accident.

One passenger told the Chicago Tribune newspaper that the train skidded out of control, and people aboard were crying and screaming.

The newspaper quotes an official with the rail system as saying a thorough investigation will take several months.

Some information for this report provided by AP and Reuters.