Some trains from Euston station have been cancelled after a points failure.
National Rail has said that a points failure between Watford Junction and Milton Keynes Central means that some lines are blocked.
It warned that some trains running between these stations may be cancelled or delayed by up to 30 minutes, with disruption expected until 6.45pm this evening (October 4).
The points failure has impacted services run by Avanti West Coast and London Northwestern Railway.
Live departure boards show that at least three trains from Euston station have been cancelled as a result of the disruption.
This includes the 5.54pm and 6.24pm services to Tring, and the 6.06pm service to Bletchley.
Avanti West Coast customers have been advised that their ticket is valid on one of the two services immediately before their booked train, or one of the two immediately after.
Those who experience a delay in completing their journey may be entitled to compensation from the relevant train company.
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