Five men and a woman suspected of terrorism offences have been arrested as part of an intelligence-led operation in London.
A man, aged 21, and a 30-year-old woman were arrested at separate addresses in west London.
A 29-year-old man was arrested in the street in west London while three other men, aged 18, 24 and 26, were detained in east London.
The arrests are not linked to the Olympics or Paralympics, police said.
The 24-year-old man was tasered during his arrest but was not taken for hospital treatment.
All six have been taken to a police station in south-east London.
Eight flats and homes in west, east and north London and one business in east London are being searched under the powers of the Terrorism Act 2000.