Services into London faced long delays this afternoon between Epsom and Guildford/Dorking when a failed train at Leatherhead blocked the lines.
A Southern Trains vehicle broke down around 4pm after striking an object and response teams reached the scene after 15 minutes.
A Southern Trains spokesman said: "The 15.04 Horsham to Victoria service struck an object on approach to Leatherhead station. The train terminated at the station as it had received damage.
"It is unknown at this point what the train struck.
"All passengers were detained at the station to continue their journeys on other services and the affected train returned to the depot for inspection and repair."
Delays of up to 30 minutes were expected, and commuters were told disruptions were likely to last until at least 5.30pm.
The incident can be followed using the hashtag #Leatherhead
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