There is disruption to rail services in Peterborough due to a trespasser on the rail lines at Spalding.
This is disrupting trains on the Peterborough/Lincoln/Doncaster route.
British Transport Police are now are the scene and Network Rail is expected there imminently.
A freight train is currently stood at a platform in Spalding, while trains on the route cannot run in both direction.
East Midlands Railway said journeys may be delayed by 30 minutes.