Police in London say they have been unable to find any evidence of gunfire after reports of an incident at Oxford Circus Tube station.
Armed police responded to reports of shots being fired.
The Met said it responded as if the incident was terrorist related and urged people on nearby Oxford Street to take cover inside buildings. Police said there were reports of shots fired on Oxford Street and underground at the Oxford Circus tube station.
Shortly after 6pm, the Met response was stood down, a statement said.
British Transport Police said officers were called following reports of gun fire on the westbound Central Line platform.
"Passengers at the station then self-evacuated the station onto Oxford Circus and Regent Street area of London," a statement said.
"This caused a significant level of panic which resulted in numerous calls from members of the public reporting gunfire.
"Officers responded in line with our procedures of a terrorist incident, this included armed officers from British Transport Police and the Metropolitan Police.
"A full and methodical search of the station and Oxford Street was conducted by officers.
"At this stage, we are examining the circumstances of the incident which resulted in the station being evacuated. During the station evacuation, one woman is believed to have sustained a minor injury."
BBC reporter Helen Bushby said she had seen a "mass stampede" of people running away from the station.
The Met said it had not located "any trace of any suspects, evidence of shots fired or causalities".
Following our call to Oxford Circus, we have been unable find any evidence of gunfire. We remain on scene alongside @metpoliceuk and advise you to avoid Oxford Circus and Regents Street areas https://t.co/z12K8zmgZ9 pic.twitter.com/K1nlCmKEJE— BTP (@BTP) November 24, 2017
In a statement on Twitter, British Transport Police said:
"Armed officers were quickly on scene, no evidence of gunfire found. The area was searched swiftly and we are working to lift cordons and reopen stations."
The incident sparked the evacuation of Oxford Circus tube station on Friday evening, when it was busy with shoppers looking for Black Friday bargains.
Extra police remain on duty.
- BBC / Reuters