Emergency services were at the scene of the incident.
Trains may be delayed by up to 60 minutes or cancelled. Disruption is expected to continue until at least 3pm. All lines are currently blocked, therefore services are unable to run between Peterborough and Hitchin.
The power to all lines has been switched off to allow Network Rail response staff and the emergency services to attend. Advice for Great Northern and Thameslink customers:
To assist you with your journey, tickets are being accepted on the following:
Fire destroys huge area of land at Great Denham Golf Course
Anglian Water rules out hosepipe ban for Bedford households
'Sophisticated crime group' behind £1.1m stolen from Luton council that was destined for a Bedford school
Man charged with burglary and assaulting an emergency worker in Flitwick
Bedford bus company revises timetable after passenger numbers review
* CrossCountry between Peterborough and Cambridge
* East Midlands Trains between Peterborough and Ely
* London Underground via reasonable routes More support Thameslink and Great Northern work closely with The Samaritans and support the work that they do.