Nine men have been arrested in London on suspicion of being members of a terrorist organisation and encouraging terrorism.
Radical preacher Anjem Choudary, 47, was reportedly among those held by officers from the Metropolitan Police Counter Terrorism Command (SO15) on Thursday.
The men, aged between 22 and 51, have been taken to police stations in central London and remain in custody on suspicion of being members of a proscribed organisation or supporting a proscribed organisation.
The organisation is believed to be Al Muhajiroun, the Press Association reported. The group was set up by Choudary and Sheikh Omar Bakri Mohammad, who was told he could not return to the UK after the 7/7 bombings. Al Muhajiroun was banned in 2010.
A number of residential, business or community properties – 11 in east London, one in west London, one in northwest London, five in south London and one in Stoke-on-Trent – are also being searched as part of the investigation.
A statement from the Met Police said: “These arrests and searches are part of an ongoing investigation into Islamist related terrorism and are not in response to any immediate public safety risk.”
This week, Choudary was reported to have said he had no sympathy for aid worker Alan Henning, who has been captured by the Islamic State (IS) in Syria.
He reportedly said: “In the Koran it is not allowed for you to feel sorry for non Muslims. I don’t feel sorry for him.”
Last month, the Government raised Britain’s terror threat level from substantial to severe because of the threat from militant groups in the Middle East.
A severe threat means an attack is deemed to be “highly likely”, but there is no intelligence to suggest one is imminent.