A train that has broken down near Stevenage is causing delays on the line heading south to London.
A points failure at Welwyn Garden City is causing disruption to trains northbound between Potters Bar and Stevenage this morning.
There are delays on the northbound line between Hitchin and Peterborough this morning after a points failure near Biggleswade.
Great Northern rail users have been warned to expect delays until the end of service today if they are travelling between Stevenage and London.
A person has been hit by train between Welwyn Garden City and Finsbury Park, blocking all lines between Stevenage and London.
Passengers on Thameslink and Great Northern will benefit from 200 extra services this December, Govia Thameslink Railway has announced.
Train services between Welwyn Garden City and London's Finsbury Park may be cancelled or delayed following an "operating incident".
A person has been hit by a train on the Great Northern line at Arlesey this morning.
Great Northern rail services are facing disruption this morning, as all lines are currently blocked between Stevenage and Huntingdon.
Some Great Northern rail services towards London are facing disruption this evening after an item was caught in overhead wires in the Sandy area.