Train passengers are facing disruption because engineering work has over-run.
Greater Anglia said on Wednesday morning that work on the lines between Norwich and Ipswich had not been completed as scheduled.
Although the lines are now open, services running to and from the two stations may be cancelled, delayed or revised, the rail operator said.
The 4.55am service from Norwich to Liverpool Street had been cancelled, along with the 6am and 7.30am service from Liverpool Street to Norwich.
Greater Anglia said disruption was expected until 9am.
A points failure at Acle also saw cancellations to train services between Norwich and Great Yarmouth. However, by 8am, that had been resolved and Greater Anglia said services would resume with the 8.09am, from Norwich and the 8.46am from Great Yarmouth.
And, in a separate issue, passengers from Cantley and Reedham wanting to catch the train to Great Yarmouth will have to go via Brundall or Norwich to get to the seaside town.
Yet more disruption has been caused by a fault with the signalling system between Stowmarket and Diss, with Greater Anglia warning services between those stations may be cancelled, delayed by up to 30 minutes or revised.
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