A 19-year-old man has been arrested under the Terrorism Act after a suspicious device was found on a Tube train.

The suspect was seized in Holloway Road, north London, in an armed operation today.

The Metropolitan Police said a Taser was discharged during the arrest but no shots were fired.

In a statement, the force said: "The 19-year-old man was arrested on suspicion of the commission, preparation and instigation of terrorism acts, under Section 41 of the Terrorism Act 2000. He has been taken to a London police station where he remains in custody."

The police swoop came after a controlled detonation was carried out on the device found on a train at North Greenwich station, close to the O2 complex in south east London yesterday morning.

British Transport Police were called to the station shortly after 11am on Thursday after train staff reported finding a "suspicious item" on a train travelling eastbound on the Jubilee Line.

The station was evacuated while specialist officers made the item safe.

Scotland Yard said the item is currently being forensically examined. No details have been officially released about the item.

The Met said: "The Met and BTP have been working tirelessly since the item was found to follow up all potential leads.

"Officers are keeping an open mind regarding any possible motive. They are not looking for anyone else in relation to this investigation at this stage."

The public were told to expect to see more officers, including armed police, in and around transport hubs.

High visibility patrols by BTP officers on the underground and at stations will remain in place today.

Police urged anyone who saw anything suspicious on the train, or anywhere else, to call the anti-terrorist Hotline on 0800 789 321.

The current threat level for international terrorism in the UK is severe - meaning an attack is "highly likely".

Mayor of London Sadiq Khan said: "Thanks to the outstanding professionalism of the Metropolitan Police, Transport for London staff and the British Transport Police, this situation was dealt with swiftly and safely, and no injuries resulted.

"I have been in constant contact with the Metropolitan Police commissioner and the TfL commissioner throughout the past two days.

"Keeping Londoners safe is my highest priority. I am urging all Londoners to check with TfL before they travel and to remain calm and vigilant at all times."

The station reopened on Thursday night and a performance at the O2 by the band Nickelback went ahead as planned.