There are delays on train services running in and out of Norwich (Image: Brittany Woodman)
Passengers were warned of disruption to train services on Friday morning.
Greater Anglia said no trains would run in or out of Norwich after a signalling system error blocked all lines.
The signalling failure impacted services from stations on the main Norwich to London line, including Diss, Stowmarket, Ipswich and Manningtree, as well as on the Lowestoft line.
A spokesman for the firm said it was working "diligently" with Network Rail to restore the timetable "as soon as possible".
Services returned to normal at around 10am.
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