Passengers travelling on Greater Anglia trains are facing delays on the Ipswich to Peterborough line this morning.
A fault with the signalling system is causing services between Whittlesea and Ely to run at a reduced speed.
Network Rail engineers are on site dealing with the issue and bosses say they are working as fast as they can to fix the fault.
The 7.50am Peterborough to Ipswich was the first Greater Anglia train affected by the disruption, which is expected to continue past the morning rush hour.
Crosscountry Trains and East Midlands services are also being delayed by up to 30 minutes.
Both Greater Anglia and Network Rail have apologised for the disruption.
Information for specific trains can be found using the JourneyCheck tool.
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