A train carrying commuters home at rush hour slammed into an empty train outside London on Thursday, killing at least one passenger and injuring 66 others.

Firefighters at the scene tried to cut their way into one of the cars to free an undetermined number of people trapped in the wreckage.

Hertfordshire police said one woman died in the accident, but could not confirm an ambulance service report of two dead.

British transport police said there were around 100 “walking wounded” at the collision site near Watford Junction in Hertfordshire, 20 miles north of central London.