An East Sussex railway line, where a major train derailment recently took place, has been closed for a precautionary safety inspection.
National Rail said the track between Haywards Heath and Lewes was being inspected just after 12:30 BST on Saturday.
The southbound line towards Lewes is blocked, but the northbound line remains open, according to Southern Rail.
It urged travellers to allow for an additional 30-45 minutes for their journeys due to the disruption, which is also impacting services to Eastbourne and London Victoria.
"Safety is always our top priority," said a Southern Rail spokesperson.
"Trains will be delayed, revised or cancelled until the inspection is complete.
"We'd like to apologise to any of our passengers affected."
The inspection comes after three carriages of a passenger train tumbled off the track in Lewes on 13 August, leaving 30 people injured.
The railway line reopened on 1 September following a major recovery operation and reconstruction work.
