Police said they had arrested more than 170 members of the right-wing English Defence League (EDL) on Friday near an Armistice Day ceremony in central London amid fears they were trying to target anti-capitalists camped in the city.
The Metropolitan Police said the group were detained to prevent a breach of the peace at a pub near the Cenotaph in Whitehall.
A police source said it was believed the group were heading towards the anti-capitalist Occupy protest camp outside St Paul's Cathedral, set up last month after being inspired by the Occupy Wall Street movement.
170+ supporters of EDL were arrested this p.m. to prevent a breach of the peace, the Met Police said on its Twitter website. No reported disorder between opposing groups at this stage.
Last year, members of the EDL, which stages protests against violent Islamism, clashed with police during a fracas at a Remembrance Day ceremony.
The trouble erupted then when members of the radical Muslims Against Crusades (MAC) group burnt two large poppies outside the Royal Albert Hall in London during a two-minute silence.
EDL founder Stephen Lennon was arrested during the disturbances.
On its website, the EDL said its members had been planning to meet in Westminster. This is about the memories of the fallen past and present,? ?and anyone who acts otherwise will only be helping MAC in disrupting the day, it said.
Earlier, counter-terrorism officers said they had carried out a raid on three premises linked to the MAC, which had planned another demonstration to disrupt Armistice Day ceremonies.
Properties connected to MAC and its leading figure Anjem Choudary, were raided late on Thursday night following the decision by Home Secretary Theresa May to ban the group and make supporting it a criminal offence.
At 11 p.m. last night, officers from the Counter Terrorism Command executed three search warrants under the Terrorism Act 2000 at addresses in east London, a London police spokesman said on Friday. There were no arrests, he added.
Choudary said his house and a community centre where the group used to teach in Whitechapel were two of the targets.
It's a fishing expedition at the end of the day -- they've got nothing on me. I haven't done anything illegal, he told Reuters. Obviously it's inconvenient, but that doesn't stop me propagating what I believe.
The group had promised a hell for heroes demonstration at the Albert Hall again on Friday. However, on its website the MAC said it had disbanded, and Choudary said the planned protest over Britain's foreign policy would now not go ahead.
I think that the objective has been achieved which is to show that the poppy and Armistice Day is a fig leaf which has been used to cover the crimes which have been committed, he said.
Our message has gone viral and global really because of the pronouncement of Theresa May so I don't see there's any point (in holding the protest).
May said MAC was the latest incarnation of organisations also linked to Choudary which had been banned, including al Muhajiroun, Islam4UK and Al Ghurabaa. Choudary said he would discuss options for a new group with colleagues.
(Reporting by Michael Holden; Editing by Steve Addison)