There is disruption to rain lines between Cambridge and Shelford after plastic sheeting became caught on overhead wires.
Greater Anglia report some lines are blocked, with services likely to be delayed or revised.
It is affecting services between London Liverpool Street and Cambridge.
Network rail engineers are on route to the site.
Disruption is expected into the afternoon.
On its website Greater Anglia say specific train service alterations are available on its online journey checker.
We will bring you updates on this incident below.
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