Passengers have been warned to expect delays until 10am following last night's serious fire near Ashford International station.
One person was seriously injured after the fire broke out at an electricity substation.
It led to huge delays across the network, with hundreds of people stranded for hours.
Lines reopened late last night but problems are expected to continue throughout the morning.
A spokesman for Southeastern said: "Due to the intensity of the fire, the signal box at Ashford had to be evacuated, which meant we had no signalling on a large area of our network, which affected most of our routes throughout the incident.
"Because of the severity of the overall incident, train services this morningwill be affected.
"We had expected some routes to remain closed until at least 07:00, but power has now been restored and services can run through Ashford.
The level of disruption means that we will still see some alterations, delays, cancellations, and short formations, all of which will be published as and when we can."
Passengers have been warned to check in advance before travelling.
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