Police at Heathrow Airport have arrested a 19-year-old man suspected of terrorist offences, the Met has said.
He was detained by counter-terrorism SO15 officers on suspicion of "preparing for acts of terrorism", according to the BBC.
A spokesman said the arrest was "Syria-related".
Scotland Yard has not yet released any details on the charges or the man's name
The force said it had searched an address in Camden, north London, but that the arrest was "not in response to any immediate risk or threat".
The teenager is being held in custody at a south London police station.
He was detained under the Terrorism Act 2006, officers said in a statement.