British police said they had not located "any trace" of shots fired or any casualties following a security alert in the Oxford Circus shopping district in London on Friday.
"To date police have not located any trace of any suspects, evidence of shots fired or casualties," London's Metropolitan Police said in a statement after being called to reports of "shots fired".
Earlier, police responded to reports of shots fired on Oxford Street and at the Oxford Circus Underground station "as if the incident is terrorist related", advising the public to clear the busy shopping street.
"Police were called at 4:38 pm (1638 GMT)... to a number of reports of shots fired on Oxford Street and underground at Oxford Circus tube station," London's Metropolitan Police said in a statement.
"Police have responded as if the incident is terrorist related. Armed and unarmed officers are on scene and dealing along with colleagues from British Transport Police," the statement said.
"If you are on Oxford Street go into a building and stay inside until further direction," it said.
London is on high alert following a string of terror attacks in Britain this year.
British Transport Police said the Oxford Circus and Bond Street stations had been evacuated and were shut, saying they were investigating a "customer incident".
An eyewitness told AFP she saw people running from the Oxford Circus station, which is particularly busy because of stores offering Black Friday discounts.