Nineteen-year-old was known to mental health services and arrested following incident at station in London

This article is more than 3 years old

This article is more than 3 years old

The investigation into a homemade device found on a London tube train is examining whether a 19-year-old suspect had links to violent Islamist ideology and was known to mental health services.

The man was tasered during a daylight arrest by armed police on a busy north London street on Friday lunchtime, 24 hours after the device was discovered by train staff at a south London tube station.

The Guardian understands the item is believed to have been a homemade device, possibly constructed with the intention of exploding. It was unsophisticated and the suspect has been detained under terrorism legislation covering the “commission, preparation and instigation” of a violent act.

At this stage it is not believed by police to have been a hoax, and the leaving of the device on a train is being treated as a deliberate act.

Since the alert, just after 11am on Thursday, experts had been examining whether the improvised device could have exploded and investigators had been hunting for a suspect.

Counter-terrorism investigators believe whoever was behind the incident at North Greenwich station was acting alone, a so-called “lone wolf”, if they establish it was terrorism.

They have not yet, and an initial check of mental health records linked to the sole suspect has led to further inquiries into material held by the health service. The part of the investigation covering the health history of the suspect is complicating the part of the inquiry trying to establish the motive.

The arrest at 12.20pm on the busy Holloway Road allowed counter-terrorism investigators to seize digital material linked to the suspect. They were looking for more, items such as phones or computers, as they searched his home in south London. The key focus of the examination will be any motive, which may be revealed by any violent Islamist material held on or visited via the internet on electronic devices.

The male had been kept under observation before being detained.

After the alert at North Greenwich station, detectives seized and examined CCTV for signs of any suspect.

The police swoop came after a controlled detonation was carried out on the device, which was discovered by a member of train staff. The station was evacuated, with passengers rushed out being told to leave “immediately”. After the controlled explosion, Scotland Yard’s counter-terrorism command was called in to lead the investigation.

The 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 incident led to extra police patrols across the capital’s transport network, described as a “reassurance” measure.

The arrest in broad daylight is unusual in a counter-terrorism investigation.

In a statement, the Met police said: “The man was arrested by officers from the Met’s counter-terrorism command, assisted by armed colleagues, in the street in Holloway Road, N7, at 12.20hrs. Officers discharged a Taser during the arrest. No firearms were discharged.

“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 UK is on a heightened state of terrorist alert stoked by fears that an attack by Islamist extremists is highly likely.

There is growing awareness among police of people with mental health problems being radicalised.







