The Transport for London (TfL) website shows the entire Bakerloo, Waterloo and City, Weaver, and Suffragette Lines are suspended.
There are also severe delays and part suspensions on the Elizabeth, Jubilee, Mildmay, and Piccadilly lines.
Multiple lines suspended and stations closed; follow latest
The Northern line is listed as having minor delays. All other lines are unaffected, according to TfL.
Several stations were forced to close after the incident around 2.30pm, including Marble Arch, Holborn, Covent Garden, South Kensington and Tottenham Court Road.
A post on X by @TFLAccess said Covent Garden was shut “while we fix faulty communications equipment”.
A spokesman for the travel network said there was an outage in southwest London for “a matter of minutes” and “everything shut down” due to a “National Grid issue”.
The spokesman said “some people would have probably been stuck in a tunnel for a little bit of time”.
National Grid said a cable fault on its transmission network in central London – and a “consequent voltage dip” – may have briefly affected power supplies.
It said the fault was “resolved within seconds” but that it caused a small fire that’s now been brought under control.
TfL said it was in the process of “getting things back up and running again” but “can’t say when it will be fixed”.
The shutters were down at the entrance to Waterloo Underground station at around 4pm – the station serves the Bakerloo, Northern and Waterloo & City lines.
Staff at Paddington station were also seen directing passengers away from the Elizabeth Line and recommending they use buses instead. The Bakerloo Line entrance was completely shut.
Alison Hendry, 33, and Joseph Richardson, 37, travelled on the Heathrow Express to Paddington after flying from Glasgow.
Ms Hendry said: “It’s a bit annoying they only told us when we got here. We walked all the way across the station, we have to go all the way back.”
“It doesn’t even bother me. But if I was in a rush, it would,” Mr Richardson added.
TfL said Embankment, Charing Cross and Putney Bridge stations had reopened after previously being forced to close.
The transport operator also said at 5.12pm that the cable car it runs over the Thames was shut due to “high lightning risk in the area”.
