Police during an intelligence-led operation, in London arrested five men and a woman suspected of terrorism offences.
A man, aged 21, and a 30-year-old woman were arrested at separate addresses in Ealing, west London.
A 29-year-old man was arrested in an Ealing street, while three other men, aged 18, 24 and 26, were detained in Newham, east London.
The arrests are not linked to the Olympics or Paralympics, police said.
Some of those arrested are British nationals and potential targets are believed to be in the UK.
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.
Norwegian
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