Bond Street - station has re-opened following a short closure due to a fire alert.
St Paul's station is currently closed due a double incident - a person under a train plus a passenger taken ill on the platform.
Emergency services are at the scene trying to rescue both passengers.
The Central Line is now shut between Liverpool Street and Holborn with delays on the rest of the line as a result.
Five teenagers were threatened at knifepoint after witnessing an attack on a Central Line train.
Four boys and a girl, all aged 14, were confronted by a man holding a flick knife at Theydon Bois in east London.
Detective Constable Carl Wayte, from British Transport Police said: "A man was attacking another passenger on an eastbound Central line train as it travelled between Loughton and Theydon Bois London Underground stations.
During the journey four boys and a girl, all aged 14, witnessed the incident and alerted other passengers.
The teens left the train at Theydon Bois and the man also left the service. “He then produced a flick knife and threatened the group on the platform"
Anyone with information is asked to contact British Transport Police on 0800 40 50 40.
Transport for London says the Central Line is running again after a signal fault at Mile End, but there are severe delays.
Central line is knackered!! http://t.co/4YzGeimI9w
I thought not getting a seat on the central line this morning would be the worst it got today... Nooooooooo http://t.co/IEUZh3j12d
Central Line is a little busy this morning. http://t.co/D3nVV7KH2x
The Central Line is completely snarled up because of faulty signals at Mile End. Central Line users being told to expect extremely slow, delayed journeys. The line will be suspended shortly between Liverpool Street and Leytonstone while engineers try to fix the problem.
Tube passengers are set to benefit from improvements on two lines.
From tonight the Central line will have increased services whilethe Waterloo and City line will finish at 12.30 am.
Terrified passengers frantically tried to escape a tube on the Central Line on Sunday, after it began filling up with smoke. Doors refused to open at Holland Park station causing mass panic among commuters. The problem is believed to have been caused by a brake fault.
(Credit: Adam Pajda)