Train journeys through Manningtree are subject to disruption for the rest of the day due to overhead electric wire damage.
Greater Anglia said services running through the station will be cancelled or revised.
Disruption will not affect mainline services - only services joining the Harwich branch from the mainline - added the rail operator.
Among trains cancelled by Greater Anglia were the 08.28am from Harwich Town to Manningtree, the 9am Manningtree to Harwich Town and the 9.28am from Harwich Town to Colchester.
Network Rail will be carrying out overnight repairs, said Greater Anglia, which apologised to customers for any inconvenience caused.
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