Armed police arrested a 19-year-old man in London on Friday under counter-terrorism laws in connection with a suspicious package found on the Underground train network that sparked a security alert.
“The man was arrested by officers from the Met’s Counter Terrorism Command, assisted by armed colleagues, in the street in Holloway Road” in north London, the police said in a statement.
London’s Metropolitan Police said they had used a taser during the arrest at around 12.20pm (1120GMT) on the busy shopping street, but that no shots were fired.
The police said they made the package safe after it was found on a train on Thursday. It was now being “forensically examined”.
“The public will see more officers, including armed police, in and around transport hubs to provide reassurance around public safety,” the statement said, adding that the London Underground was working as normal.
Counter-terror detectives opened an investigation on Thursday after the suspicious item was reported at around 11 am (1000 GMT) on a train at North Greenwich station, which serves The O2 entertainment complex, formerly the Millennium Dome.
The police said in a statement on Thursday that “a controlled detonation” of the package had taken place.
“Officers are keeping an open mind regarding any possible motive,” added the statement. “They are not looking for anyone else in relation to this investigation at this stage.”
Since August 2014, the terror threat level in Britain has been classed as “severe” -- the second highest level, meaning an attack is considered “highly likely”.
London mayor Sadiq Khan praised the “outstanding professionalism” of police and Transport for London staff.
“This situation was dealt with swiftly and safely, and no injuries resulted,” he said.
“Keeping Londoners safe is my highest priority. I am urging all Londoners... to remain calm and vigilant at all times.”