A fire next to the track in west London is creating long delays on the London Overground.
The blaze, between South Acton and Acton Central stations is causing disruption to services running between Richmond and Acton Central.
National Rail has warned that trains running between these stations may be cancelled or delayed by up to 20 minutes.
Disruption is expected until 4.45pm.
Earlier on Wednesday, trains from London Euston were hit by half-hour delays due to a points failure in north-west London.
Services between Euston and key stations such as Birmingham New Street, Manchester Piccadilly, Liverpool Lime Street and Glasgow Central have been disrupted by the issue near Wembley Central.
Avanti West Coast, London Northwestern Railway and Southern services were been disrupted.
