All trains are being cancelled between Stansted Airport and London Liverpool Street due to a "broken rail".
The issue was first reported by Greater Anglia at around 9am this morning and disruption continues.
All services between the two stops have been cancelled until around 2.30pm but this could change.
The broken rail is said to be on the approach to the airport and it has been deemed unsafe for trains to run over it.
As a result services are unable to run in and out of the airport until the rail has been inspected and replaced if required.
The Norwich to Stansted route via Cambridge is also affected.
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