Nine people were arrested in London on suspicion of being members of an outlawed group, a media report said Thursday.
The arrests were made after police raided at least 18 properties in London and one in Stoke-on-Trent, BBC reported, adding that it was part of an ongoing probe into Islamist-related terrorism.
Those arrested included radical Islamist preacher Anjem Choudary, the former head of the Islamist group al-Muhajiroun in Britain or Islam4UK, that was banned in 2010.
Police have arrested all the suspects under various sections of the country's anti-terrorism law, an official statement said.
The arrests were carried out by the Met's Counter Terrorism Command (SO15) who are holding them for questioning at police stations in central London.