A 19-year-old man has been arrested on suspicion of sharing extremist material.
The man was arrested at an address in east London on Friday, the Metropolitan Police’s Counter Terrorism Command said.
He has been taken to a police station where he remains in custody.
In a statement, Commander Richard Smith, of the Met’s Counter Terrorism Command, urged the public to be the Met’s “extra eyes and ears”.
“Every day, teams within the Met and across Counter Terrorism Policing nationally, carry out proactive investigations to identify and target those we suspect of being involved in terrorism”, he said.
“We require the public to be our extra eyes and ears and I would encourage anyone who has information that could assist counter terrorism police to call us in confidence and share information. Your call won’t ruin lives, but could well save them.”
Officers continue to search the address in east London.