An 18-year-old man has been arrested on suspicion of carrying out Friday’s explosion on the London Underground.
According to the BBC, the man — who remains unidentified — was held in Dover on Saturday before being taken to a police station in Kent. He is expected to be taken to a South London police station later in the day.
Metropolitan Police Deputy Assistant Commissioner Neil Basu said in a statement the arrest is “significant in our investigation” but the terror threat level remains at “critical” — the highest level, and meaning another attack is imminently expected.
At least 30 people were injured after the crude explosive wrapped in a plastic grocery bag and concealed in a bucket went off on a train at Parsons Green station at 8:20 a.m. on Friday.
Though most injuries were minor, three people remain in Chelsea and Westminster hospital in central London.
Armed police are expected to be present at London Underground station following the attack, as well as “military personnel” on the streets and elsewhere.
Sadiq Khan, the mayor of London, said the increased law enforcement presence is “to keep us safe.”
The Islamic State claimed responsibility for the attack in a statement, describing the perpetrator as a “detachment” of its militants.
According to reports, the man was arrested after police officers talked to witnesses and combed through hours of CCTV coverage of London Underground.
The attack is the fifth major one in Britain in less than six months, and the first on mass transit since deadly bombings killed 52 people in 2004.
