An investigation has been launched after a train travelled the wrong way down a stretch of the London Underground, almost leading to a head-on collision.
Transport for London (TfL) confirmed a Chiltern Railways service stopped a few metres in front of a Tube train at Chalfont & Latimer station, in Buckinghamshire, on Sunday night.
An image from the scene shows the two trains just metres apart on the Metropolitan line.
Part of the track has been damaged by the incident, though no casualties were reported.
A TfL spokesperson said: “We apologise to customers disrupted by the closure of the Metropolitan line between Chalfont & Latimer and Chesham.
“This is the result of an incident involving a Chiltern Railways train near Chalfont & Latimer station last night.
“We are working with Chiltern Railways to determine exactly what happened, and our engineers will repair the railway to return it to service as quickly as possible.”
The Metropolitan line remains suspended between Rickmansworth and Chesham.
Chiltern Railways said it was working with the Rail Accident Investigation Branch to “understand the causes of this incident”.
“We apologise for the disruption caused to customers using Chiltern Railways and London Underground services in the area,” a spokesperson added.