Commuters are facing cancellations and delays to their journeys after a freight train derailed in the early hours of the morning.
Operator Great Northern said on Twitter the train had partially come off the tracks at a siding just to the north of Hitchin station in Hertfordshire.
The accident meant trains were unable to use platform one at the station.
Services from Peterborough and Cambridge to London were delayed or cancelled but all lines are now open.
However, Great Northern said passengers travelling towards London from those two stations, and from Hitchin, should expect “residual delays and cancellations” until about 12:30 GMT.