The Circle Line on the tube is currently suspended completely while emergency services respond to a person on the track.
Transport for London (TfL) said there was no service on the entire line, and valid tickets would be accepted on any other reasonable route including buses.
There are also ‘severe’ delays on the District Line, which serves much of the same route and is suspended eastbound between Earl’s Court and Embankment.
A status update from TfL said: ‘Circle Line: No service while emergency services deal with a causality on the track. London Buses and Mildmay line are accepting valid tickets via any reasonable route.’
The Circle Line is one of the most widely used on the network, serving crucial transport hubs including Victoria, Westminster, Liverpool Street, King’s Cross, and Paddington.
Elizabeth Line and Piccadilly Line also disrupted
Travellers are also facing major issues on two other lines.
The Piccadilly Line is part suspended, with no service between Rayners Lane and Uxbridge ‘to prevent damage to train wheels caused by expected significant leaf fall’.
There are also severe delays on the Elizabeth Line, which is part suspended between Whitechapel and Stratford, while engineers are work to fix a signal failure at Whitechapel.
Elsewhere, there are minor delays on the Hammersmith and City Line, and on the Weaver branch of the Overground.
All other lines are operating as usual, the transport body said.
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