A 20-year-old man has been arrested by counter-terrorism police after raids in the capital on Wednesday.
The man from Brent was detained in Kensington and Chelsea at around 11.10am on suspicion of collection of information likely to be useful to someone preparing a terrorist act.
He is currently in custody at a south London police station.
Warrants were also executed at four addresses in north London and searches are ongoing, police said.