A 21-year-old man has been arrested in east London on suspicion of terrorism offences.
Officers from Met Police arrested the man at a "residential address" before taking him into custody in south London.
Scotland Yard said the man is being held on suspicion of the commission, preparation or instigation of acts of terrorism.
A police spokesman said: "Officers from the Met's Counter Terrorism Command have arrested a man in east London for terrorism offences.
"The 21-year-old man was arrested at a residential address in east London on suspicion of the commission, preparation or instigation of an act of terrorism under Section 40 (1) (b) Terrorism Act 2000.
"He was detained under TACT and taken to a south London police station where he currently remains in police custody.
"As part of the investigation, officers are also carrying out a search at the east London address."
Enquiries continue.
