Southeastern has said it believes the fire on one of its trains this week is “completely unrelated” to the trackside fire at Charing Cross station 10 days ago.
The investigation is ongoing, and expected to conclude soon, but a spokesman told City A.M. that two incidents were not thought to be connected.
The 17:56 from Victoria to Dartford caught on fire on Wednesday evening, with these Vines shot by a passenger showing how sparks turned to flame, and ultimately an explosion.
No passengers or staff were injured and the area was evacuated so emergency services could deal with the fire under the train.
It followed a trackside fire at Charing Cross station on November 24, which caused commuter chaos (albeit relatively briefly).
The cause of that fire has now been determined as an electrical fault on the track, Southeastern's spokesman said.
“That then led up the exterior of the train and caused damage to the exterior of the train,” he added.
The Denmark Hill incident is being investigated to establish whether it was the train itself or whether the train had hit something while moving.