Buses will replace trains between Norwich, Great Yarmouth and Lowestoft this morning after problems with the railways.
Greater Anglia said train faults had forced the cancellation of services.
Rail replacement buses have been laid on to get passengers to their destinations.
They said disruption was expected until further notice.
Greater Anglia and Network Rail apologised to people whose journeys have been affected by the disruption.
Trains affected included the 7.32am and 8.47am from Great Yarmouth to Norwich, the 7.50am from Lowestoft to Norwich, the 7.55am train from Norwich to Lowestoft and the 8.09am service from Norwich to Great Yarmouth.
The 11.36am from Norwich to Great Yarmouth and the 12.17pm from Great Yarmouth to Norwich were initially cancelled, but have since been reinstated.
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