British Home Secretary John Reid has been heckled during a speech about targeting potential Muslim extremists
He was interrupted by activist Abu Izzadeen, who said he was "furious" about "state terrorism by British police".
In his speech, Mr Reid asked Muslim parents to keep a close eye on their children and act if they suspected they were being radicalised by extremists.
It was his first speech to a Muslim audience since becoming home secretary.
The protester, also known as Omar Brooks, denies being a member of the banned al-Ghurabaa group.
He accused the minister of being an "enemy" of Islam before he was led from the building by police and stewards.
Respect MP George Galloway, in an open letter to Mr Reid written on Wednesday afternoon, asked how such a "well-known extremist... was allowed within punching distance of the British home secretary".
A Home Office spokesman said that, while Mr Izzadeen was not invited to the meeting, it was "in the nature of an open community meeting... that some people who were not invited ended up attending.
"There was no question of the home secretary's safety being compromised at any time."
A second heckler, who also interrupted Mr Reid's speech, was ejected a few minutes after Mr Izzadeen.
UK: Muslim Fanatic Omar Brooks Disrupts Minister's Speech
Reid hijacked in approach to Muslims
'Martyrdom is praiseworthy'
Reid's message to Muslims is drowned out by radicals
Convert who calls for Islamic state
Reid: parents must heed 'tell-tale signs' of extremism
Muslims' fury as they are told to keep watch on their kids
Reid faces down hate preachers
Extremist shows face of hate