Passengers smashed their way out of a tube train in south London after a fire warning was issued on Friday night.
The northbound train stopped at Clapham Common station at around 17:50 BST when people were seen breaking the train’s windows and climbing out.
According to British Transport Police (BTP), there have been no reports of any injuries.
A spokesman for Transport for London (TfL) said: “Firefighters were on the scene and confirmed there was no fire.”
The warning at the station was attributed to a technical fault related to the exhaust fans on the train, the operator told BBC London.
The TFL said an investigation into the incident was underway, adding: “We apologize for the incident caused at Clapham Common.”
A spokesman for London Fire Brigade said around 500 people had disembarked before crews from Battersea, Tooting and Brixton arrived on the scene.
“Investigations are ongoing, but reports of smoke are believed to have been caused by the train’s brakes,” they added.
In a statement on Twitter, BTP said: “The problem is believed to be caused by brake dust, which can often be confused with fire.”
‘Screaming and shouting’
Jamie McConkey, who was on the platform, said there was “a strong smell of smoke” inside the station and people were “screaming” to get off the train.
“I could hear people banging inside the window and there were passengers on the platform who started trying to open the door,” he told BBC London.
“It looked pretty scary. I ran over and people were banging on the windows, some of them screaming and trying to get through the door.
“The door just got completely stuck. Everyone was trying to twist them open, including me.
“There were arms and legs sticking out and people seemed really, really scared. Some people looked as white as paper.”
One passenger on board said: “We were all trapped inside the Tube with the doors locked.
“We could hear people at the other end of the Tube screaming and banging on doors and windows to get out of the subway car.
“We didn’t know what was going on. People on the platform and in the Metro were banging on their windows to get out. Now I realize that it was because the subway cars were full of smoke.”
TfL said there have been severe delays on the Northern Line due to the incident.