Two men have handed themselves into police over an incident that sparked a mass evacuation at Oxford Circus Tube station in London.
Several people were injured and nine were taken to hospital, including one with leg injuries, after panic erupted in the packed station on Friday.
Armed police raced to Oxford Circus Tube station and Oxford Street after receiving 999 calls reporting that shots had been fired.
British Transport Police said the incident is believed to have started when an altercation erupted between two men on the platform.
The force said two men, aged 21 and 40, attended a police station voluntarily and were interviewed, following an appeal.
Chief Superintendent Martin Fry said: "I would like to thank the public and the media for assisting us with this witness appeal."
There was panic among rush-hour commuters and Black Friday shoppers in central London after police responded to reports of shots fired,
Stuart Crichton, London Ambulance Service assistant director of operations, said: "We checked over and treated several patients who sustained injuries while leaving the Oxford Circus area.
"We discharged seven patients at the scene and took eight patients to two central London hospitals for minor injuries.
"We also took one patient to a major trauma centre for leg injuries."
Around 90 minutes after responding, police said there was no evidence of any shots, casualties or suspects.
The station was reopened, cordons removed and the area returned to normal, with the Royal Variety Performance at the nearby London Palladium going ahead as planned.
The Met said in a statement: "Given the nature of the information received, the Met responded in line with our existing operation as if the incident was terrorism, including the deployment of armed officers.
"Officers working with colleagues from British Transport Police carried out an urgent search of the area. No casualties, evidence of any shots fired or any suspects were located by police."
BBC producer Helen Bushby described the panic, saying: "I was just walking down from the BBC towards the Tube and there was a mass stampede away from the Tube as fast as they could.
"They were crying, they were screaming, they were dropping their shopping bags. It was a very panicked scene.
"People said they heard a gunshot and panic was just spreading."