'Incidents' spark Tube evacuation
Emergency services have been called to three Tube stations after "incidents", Scotland Yard said.
Police confirmed they had been called to Warren Street, Oval and Shepherd's Bush stations.
There have been reports of smoke coming from two of the stations and all three have been evacuated.
The whole of the Northern Line has been suspended, along with the Victoria Line and the Hammersmith and City. There are no reports of any casualties.
A spokesman for London Underground said the nature of the incidents was unknown.
One hospital, near Warren St station, has started its emergency plan.
Sosiane Mohellavi, 35, was travelling from Oxford Circus to Walthamstow when she was evacuated from a train at Warren Street.
"I was in the carriage and we smelt smoke - it was like something was burning.
"Everyone was panicked and people were screaming. We had to pull the alarm. I am still shaking."
But a BBC reporter outside Warren St station said there was no sign of smoke outside.