Trains between Hastings and Ashford International are subject to delays due to a broken down train.
Southern said the train at Pevensey Bay has blocked the line towards Hastings and Ashford International.
Southern said: “The 9.46am London Victoria to Ore service developed a fault at Pevensey Bay. The driver reported an issue with the on-board radio communication system and the train was unable to move until this had been resolved. The train has now moved but this has caused delays to other services which were backed up.
“In addition to this, in a separate incident, the level crossing barriers at Hampden Park have developed a fault with the traffic lights system which warns of oncoming trains, therefore trains are having to run at a reduced speed through this area.”
Services to and from Eastbourne are subject to delays of up to 30 minutes. Short notice alterations and cancellations will take place, as trains have to run at a reduced speed through the Hampden Park area.
Services running between Eastbourne and Hastings/Ashford International are subject to delay, cancellation and alteration following a broken down train at Pevensey Bay.
Ticket acceptance is in place on Southeastern services between Ashford/Hastings and London Victoria/Cannon Street.
Disruption is expected to continue until 3pm.