Services on the London Liverpool Street to Norwich line were cancelled due to a fire at a recycling centre near the railway between Ipswich and Stowmarket.
The 'large' blaze beside the railway line near Needham Market prompted Suffolk fire brigade to request that all trains were stopped for safety reasons at around 5.40pm.
Services were running again by around 7pm, but with delays of up to 60 minutes - which was still the case at 9pm.
The fire was at a recycling centre called Sackers in the village of Great Blakenham.
Passengers were advised via the on-board announcements that there had been an explosion at the Sackers site in Gipping Road.
Suffolk Fire and Rescue had six appliances at the site in Gipping Road, to deal with the fire.
A fire service spokesman said no one was injured.
The fire was visible from the A14 and has lead to train services being cancelled along that stretch of the railway.
Trains from Norwich had earlier been terminating at Stowmarket, and trains from London Liverpool Street had been terminating at Ipswich.
Disruption is expected until 9.30pm.
A statement from Abellio Greater Anglia said: 'We are sorry for the extended journey time and disruption to your travel plans that will be caused by this incident.'
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