Armed police have arrested a teenager on suspicion of terrorism, Scotland Yard said.
The 18-year-old was detained at 12.10am in a north London street by officers from the Metropolitan Police’s Counter Terrorism Command.
He was arrested on Friday on suspicion of preparation of terrorist acts and taken into custody at a south London police station, where he remains.
A spokesman for the force said: “The arrest took place in the street in the north London area and was carried out with the assistance of armed officers.”
It is understood the arrest does not relate to suspected attack planning, and is not linked to Saturday’s royal wedding.
It comes days after the head of MI5 warned of the “intense” and “unrelenting” terrorist threat facing the UK and its European allies.
Revealing that police and the security services have thwarted 12 Islamist plots since the Westminster atrocity in March last year, Andrew Parker said the “unprecedented tempo” of attack planning in Britain shows no signs of abating.
Speaking on LBC radio on Friday, Met Police Commissioner Cressida Dick said of the 12 foiled plots: “They are all ones where the security services assess that, if we had not intervened when we did, there would have been a lethal attack.
“Some have been closer than others; some of them have been very close to the ghastly moment.”
Counter-terror agencies are also confronting a growing far-right threat.
In February, police reported that four extreme right-wing attack plots were stopped last year.
Police and MI5 are mounting more than 500 investigations at any one time, relating to around 3,000 individuals.
There is also a wider pool of 20,000 former “subjects of interest” who have previously featured in probes and who are kept under review.
The Government will unveil an updated counter-terrorism strategy within weeks.
Powers available to police and security services were reviewed after Britain was hit by five attacks last year.
Reports have suggested the strategy will set out proposals to share information about suspects more widely and introduce longer prison sentences for some terror offences.