Armed police have been stood down and two London Underground stations have reopened following reports of gunshots being fired at Oxford Circus.
Police say they received reports of shots being fired in a number of locations near Oxford Street, saying there was “significant” panic.
Officers said they had not located “any trace” of any suspects, evidence of shots fired or casualties.
Oxford Circus and Bond Street Tube stations have both reopened.
British Transport Police said one woman sustained a minor injury in the panic, as passengers fled from Oxford Circus station – in what witnesses said was “a stampede” of people.
The Met said it began receiving “numerous” 999 reports of gunshots in Oxford Street and at Oxford Circus station at 16:38 GMT.
The force deployed armed officers, saying it treated the incident as if it was terrorist related.
The Oxford Circus junction – where Oxford Street and Regent Street meet – was cordoned off, while shops and businesses were placed in lockdown.
Nearby Bond Street station was also closed to prevent overcrowding.
“Officers working with colleagues from British Transport Police carried out an urgent search of the area.
“No causalities, evidence of any shots fired or any suspects were located by police,” the Met said in a statement.
Scotland Yard said the operation had been stood down at 18:05.
British Transport Police said there had been reports of gunfire on the westbound Central Line platform at Oxford Circus.
“This caused a significant level of panic which resulted in numerous calls from members of the public reporting gunfire,” the force said.
“A full and methodical search of the station and Oxford Street was conducted by our specially trained firearms officers.
“During the search officers did not find any evidence of gunfire at the station,” it added.
The force said one woman sustained a minor injury in the panic at Oxford Circus station.
‘Dropped shopping bags’
Police said additional officers would remain on duty in the West End to reassure the public.
In a statement, Mayor of London Sadiq Khan praised the city’s emergency services for a “swift response”.
A Kensington Palace spokesman said the Duke and Duchess of Cambridge will still attend the Royal Variety Performance, at the nearby London Palladium.
“Their arrival will be delayed, but we hope they will be able to arrive in time for the start of the performance,” a spokesman said.
The scare happened on Black Friday, at a time when Oxford Street and the surrounding areas were filled with shoppers.
BBC reporter Helen Bushby said she had seen a “mass stampede” of people running away from the station in the panic.
“They were crying, they were screaming, they were dropping their shopping bags. It was a very panicked scene,” she added.
“People said they heard a gunshot and panic was just spreading.”
She spoke to a group of young women at Topshop, in Oxford Street, who said people had dropped their shopping and ran as quickly as they could.
Greg Owen, 37, from London, said he was at Oxford Circus station when people began running away.
“I was next to the Tube station and everyone started screaming and shouting and then a flood of people came up the stairs,” he added.