Commuters faced delays this morning after a power cable fire near the tracks at Kensington Olympia blocked all lines in and out of the station.
National Rail said trains are unable to call at the hub, while services between Clapham Junction and Willesden Junction or Milton Keynes Central will be cancelled until around 1.30pm.
It has also caused issues for London Overground services.
Affected passengers are able to use London buses, the Underground and Southern services via reasonable routes.
A National Rail statement said: "At 03:13, a freight train driver reported a smouldering item next to the railway near Kensington Olympia.
"Investigations have shown the burning equipment to be a pair of smouldering power cables. These would normally supply power to electric passenger trains travelling through the area."
Network Rail is responding with specialist engineers at the scene, the statement added.
