Trains have been replaced with buses between Skegness and Boston due to a fault with the signalling system which is affecting ten level crossings.
Rail operators say this has been caused by a lack of external power to the signal box.
Trains are disrupted on the Nottingham/Grantham/Skegness route.
Network Rail are expected on site shortly in order to investigate the problem.
All Nottingham to Skegness trains on the route will terminate at Boston. The last train to run through to Skegness was 0550 Nottingham to Skegness and the last train returning from Skegness will be 0810 Skegness to Nottingham.
An East Midlands Trains spokesperson said: “We don’t have an estimated time for the fault to be repaired but will have more information once the Network Rail teams have arrived on site.
“We have buses running between Boston and Skegness and are working with our suppliers to have standby buses where they may be required.”