Counter-terrorism arrest over North Greenwich Tube device
A 19-year-old man has been arrested after a suspicious device was blown up in a controlled explosion at a London Tube station.
Officers discharged Tasers during the arrest on Holloway Road, north London, but no firearms were discharged.
The suspect was taken to a London police station, where he is in custody.
Police have said they are stepping up patrols across London's transport network following Thursday's discovery of the item at North Greenwich station.
The Met Police said the device was due to be forensically examined.
The arrested man was white, bearded and wearing a hoodie, a witness said.
Ali, aged 30, who did not give his full name, said the man had been walking along the street "normally" when police descended.
"The armed police, I think five of them, ran behind him and put him on the floor," he said.
"They were shouting 'armed police, don't struggle'. Everything happened so quick."
The suspicious object was discovered on an eastbound Jubilee Line train at the south-east London station at about 11:00 BST.
A source told the BBC the device was found by a member of the public and handed to a Tube driver.
The driver treated it as a suspicious and said it contained "wires and possibly a clock".
The station was evacuated and members of the Met's bomb squad carried out the explosion, after the item was described as looking "real enough".
The Metropolitan Police and British Transport Police said there would be more police officers in and around transport hubs in the capital to provide reassurance about public safety.
London Mayor Sadiq Khan also praised the professionalism of the police and Transport for London (TfL) staff.
Mr Khan also urged all Londoners to "check with TfL before they travel, and to remain calm and vigilant at all times."
Rail union bosses had earlier called for a security summit after the suspect device was found.
The Met said officers were keeping an open mind regarding any possible motive but said they were not looking for anyone else in relation to their investigation at this stage.
The current threat level for international terrorism in the UK is severe - meaning an attack is "highly likely".