The Victoria line has been partly suspended due to a signal failure sparking travel chaos for London Tube passengers.
There are severe delays across the whole line, and Transport For London has advised taking alternative routes using tickets on the London Overground and Buses.
There is no service for seven stops between Walthamstow Central and King's Cross St Pancras after a signal failure at Seven Sisters.
The Victoria line section of the Tube stretches from Brixton in south London to Walthamstow Central in north-east London.
The Metropolitan Line is experiencing some minor delays between Harrow on the Hill and Aldgate due to a faulty train at Finchley Road.
There is no service on the London Overground between South Tottenham and Barking to allow Network Rail to repair damage caused by a derailed freight train last week. There are minor delays between Gospel Oak and South Tottenham.
All other Tube lines are experiencing a good service.
