Commuters are facing rush-hour disruption in London as delays and a part-suspension hit lines across the capital.
The Circle line has minor delays at 4.30pm on Monday due to an earlier signal failure, a spokesman for Transport for London said.
People using the Hammersmith & City line also faced minor delays after a signal failure.
The London Overground was partly suspended between South Tottenham and Barking at rush hour.
TfL said this was to allow Network Rail to "repair damage caused by a derailed freight train last week".
Elsewhere on the line there are minor delays between Gospel Oak and South Tottenham and between Watford Junction and Euston due to an earlier signal failure.
Meanwhile, people travelling on TfL Rail faced severe delays between Liverpool Street and Shenfield due to an earlier faulty train.
"A reduced service will operate between Maryland, Forest Gate and Manor Park," TfL said.
