Police were called to an emergency between Milton Keynes Central and Watford Junction
Trains via Watford Junction station have now resumed after emergency services dealt with an incident.
This story has been updated, after trains were delayed or cancelled this afternoon (January 20).
Emergency services were called to the railway line between Milton Keynes Central and Watford Junction.
For now, it has not been specified where emergency services have been called to and what for.
The National Rail warned that trains between these stations may be cancelled, delayed or revised until around 5pm.
At 4.44pm, an update confirmed that the incident has been dealt with and trains are running normally.
The National Rail and British Transport Police have been contacted for more information.
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