Police have released CCTV images of two men believed to have been involved in a fight that triggered a mass panic at Oxford Circus.
The station was evacuated during rush hour on Black Friday as the area was packed with shoppers and commuters.
Panic spread as fears of a terror attack took hold and armed police and fire crews were scrambled to the scene amid reports shots had been fired on the Tube.
People sheltered in shops and restaurants while police investigated the scene, but after extensive searches no evidence could be found and the station reopened.
Now the initial panic has been traced back to an 'altercation' on a platform at the station – and police are hunting two people they think may have been involved.
"Anyone with information, big or small, should get in touch," the British Transport Police (BTP) said in a statement.
"Officers believe an altercation erupted between two men on the platform. They would now like to speak to these two people in the CCTV images, who they believe may have information about the incident and the circumstances around the incident."
Londoner Regan Warner tweeted saying she was waiting to board the Central Line when the fight began.
"A man five foot from me bumped into another man on the overcrowded platform. They exchanged words, then a punch to the gut. Then a full out fight," she said.
"People were trying to break it up. Lots of yelling. People were running away, a woman fainted, children were scared and crying. The emergency button was pushed. The fight was broken up and the parties walked in opposite directions. Announcement to evacuate the station. I jumped on train."
The BTP said its officers received reports of shots fired on the westbound Central Line platform at Oxford Circus at 4.37pm, as passengers fled up exits towards Oxford Circus and Regent Street.
“This caused a significant level of panic which resulted in numerous calls from members of the public reporting gunfire,” a spokesperson said.
Investigators subsequently said that there was no "evidence of any shots fired".
BTP Chief Superintendent Martin Fry said: “Thank you to everyone for bearing with us this evening and also to colleagues from all the emergency services who helped carry out a swift response.
“Our officers, alongside those from the MPS, reacted quickly and responded professionally in line with our well prepared plans.
“I know incidents like these can cause concern, but our officers are highly visible around the network and across the country so if you ever need us please call us on 0800 40 50 40 or text 61016.”
London Ambulance said nine people were taken to hospital for injuries, including one who was taken to a major trauma centre for leg injuries.
Eight others were treated and discharged at the scene.