Police are investigating what caused panic among thousands of rush-hour commuters and Black Friday shoppers in the heart of central London.
Armed police raced to Oxford Circus Tube station and Oxford Street after receiving 999 calls reporting that shots had been fired.
But around 90 minutes after responding, police said there was no evidence of any shots, casualties or suspects.
Oxford Circus Tube and Bond Street stations have reopened, most cordons have been removed and the area has returned to normal.
This includes the Royal Variety Performance at the nearby London Palladium going ahead as planned, although the arrival of the Duke and Duchess of Cambridge has been delayed.
British Transport Police received reports at 4.37pm of gunfire on the westbound Central Line platform. Shortly afterwards the Metropolitan Police also took similar calls.
In a statement the Met said: “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.”
Passengers fled the station on to Oxford Circus and Regent Street causing a minor injury to one woman.
BTP said there was “a significant level of panic”, adding that it was “examining the circumstances of the incident which resulted in the station being evacuated”.
Describing the panic, BBC producer Helen Bushby said: “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.”
Jace Tyrrell, of the New West End Company, said it was a relief once it was confirmed to be a false alarm.
He added: “The police service acted extremely quickly and efficiently to secure and lockdown the area, demonstrating how incredibly well prepared they are to respond.
“Retailers, restaurants and businesses also came together to protect the public and their staff.
“This is a very high footfall area and safety and security are number one priorities for everyone working in the district.
“A police presence remains in the area to support the public.”
Here is a timeline of the events on Oxford Street on Friday which sent thousands of people fleeing to safety:
1637 - British Transport Police receive a report of “shots” being fired on the platform at Oxford Circus underground. Armed officers attend.
1638 - Scotland Yard also begin to hear of “shots fired”. It is initially described as “an incident”.
1643 - London Fire Brigade send three fire engines and 15 firefighters to the scene. People are told to avoid the area.
1656 - Transport For London (TfL) post a tweet: “Oxford Circus Station is closed while we investigate a customer incident. All trains are not stopping and paper tickets will be accepted on local buses.”
1700 - Pop singer Olly Murs tells his nearly 8 million followers: “F*** everyone get out of @Selfridges now gun shots!! I’m inside.”
1708 - Murs adds: “Evacuating store now!!! F*** heart is pounding.”
1730 - BTP confirm they have received “one report of a woman sustaining a minor injury when leaving Oxford Circus station”. There are no other reported casualties.
1735 - Kensington Palace say they are “aware” of an incident affecting the area around London Palladium, due to host the evening’s Royal Variety Performance which the Duke and Duchess of Cambridge are scheduled to attend.
1742 - Met say they have no trace “of any suspects, evidence of shots fired or casualties”.
1747 - TfL confirm Oxford Circus and Bond Street stations have both reopened and all trains are stopping normally.
1805 - Scotland Yard say the operation has been stood down.