A woman has survived being 'dragged under a train' at Clapham South during morning rush hour, with fire fighters reportedly having to jack it up to get her out.

Commuters expressed their shock on Twitter over the incident, which caused huge delays and completely shut down services on the London Underground Northern Line between Kennington and Morden.

One user, @krunchie_frog, said she was "still shaking" after hearing "screaming" while on board the train.

Others reported seeing fire fighters jacking up the train to get the woman out.

There was much confusion about how the incident occurred, with some claiming they saw the woman, who was in her twenties, "get pushed" under a train by accident. One eyewitness said the woman’s coat had become caught in the train doors as it pulled away and she was dragged beneath the carriage.

Other talked of fears about the number of people at the busy Tube station – but TFL said that the incident was not due to overcrowding.

Nigel Holness, LU’s Operations Director, said that the passenger "fell" between the train and the tracks.

“Just before 8am this morning a passenger fell between the train and tracks at Clapham South station," he said.

"The passenger has been recovered by the emergency services with non-life-threatening injuries. There was no service from Morden to Kennington for around an hour, while the rest of the line had minor delays. The service has now resumed."

Police and ambulances were at the scene. The London Fire Brigade said two fire engines and a fire rescue unit were sent to the station and they used a "scoop stretcher" to rescue the woman.

British Transport Police said the incident was not being treated as suspicious, and inquiries were ongoing to establish "exactly what happened".

While not directly linked, the incident has, however, renewed calls for TFL to address the problem of overcrowding.

The delays came following signalling problems south of the station and by a person being hit by a train (PA)

Last week, commuters were seen jumping over and diving under ticket barriers at London Bridge, that were shut to control crowds amid an escalating crush of thousands of people.

Others were stranded on platforms for at least 45 minutes in what Boris Johnson and unions described as travel “chaos”.

Passengers at London Bridge station, as unions and politicians have called for urgent action to avoid a repeat of the 'life threatening chaos' (PA)

The Mayor of London had said: “This chaos must end now. The scenes at London Bridge were completely unacceptable.