Oxford Circus Underground station in London was evacuated while police investigate a "customer incident," British Transport Police (BTP) have confirmed. Armed police are on the scene.
Police have told people to take cover inside buildings, while officers respond to reports of an incident at London's Oxford Circus Tube station.
"If you are on Oxford Street go into a building and stay inside until further direction. Avoid travelling to the Oxford Street area. At this stage police have not located any casualities," the Met Police said on Twitter.
It said the police were called at 16:38 hours (local time) today to a "number of reports" of shots fired on Oxford Street and underground at Oxford Circus tube station.
"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," it said in a statement.
"At this stage the police have not located any casualities," the statement added. Armed officers of the metropolitan police and transport police were at the spot.
"Three fire engines and 15 firefighters are in attendance at the site," the London Fire Brigade said on Twitter. Nearby Bond Street Tube station had also been closed, to prevent overcrowding in wake of the incident.