Al-Muhajiroun is a small, radical organisation based in London and run by Sheikh Omar Bakri Mohammad, who claims to be the spokesman in Britain for Osama bin Laden's International Islamic Front for Jihad Against Jews and Crusaders.
It has gained notoriety since the 9/11 attacks in the United States. Many followers openly praise the attacks and refuse to condemn murders and terrorist attacks such as the Madrid bombing committed in the name of Islam.
Bakri has followed a radical path most of his life. He was expelled from his native Syria in 1982 for taking part in a revolt against the government of President Hafez Assad. He sought asylum in Britain in 1985 after being deported from Saudi Arabia for involvement with the Jeddah branch of the Islamic Liberation Party, the Hizb ut-Tahrir.
Security and intelligence organisations such as MI5, which keep al-Muhajiroun under constant surveillance, number its adherents anywhere between 300 and 800, and say most are young, disaffected Muslim men who can be expected to grow out of their radicalism and leave the organisation within a few years.
While the al-Muhajiroun no longer has representation in any of Britain's 1,000 mosques, members believe it is their duty to proselytise and ready
themselves for jihad, or holy war, if called upon to do so.
Bakri is on the record as saying he has recruited young British Muslims to fight in Afghanistan, Chechnya and the Balkans, and has sent youths to military training camps in South Africa, Nigeria, Afghanistan, Kashmir and the US.
He has called two consecutive British prime ministers, John Major and Tony Blair, "legitimate targets". He regularly retracts such inflammatory statements.
He claims protection under a so-called covenant with Britain's security forces, a quid pro quo arrangement in which he says he is left alone to pursue his aims as long as he does not sanction attacks on British soil.
According to Khalid Kelly, the demands of the extremist al-Muhajiroun are:
"For America to stop supporting the state of Israel militarily and financially; to remove their troops from Saudi Arabia; to stop supporting the tyrant apostate rulers of Muslim countries like Egypt, Jordan and Syria and allow the mujahideen to take over; to take their troops out of Afghanistan and Iraq; to let Muslims sort out their own affairs."
Al-Muhajiroun's website features statements from bin Laden, complete with analysis and comment. The latest, posted on April 22nd, warns Western nations to withdraw their troops and personnel from "Muslim land" within three months. "For those who reject reconciliation and want war, we are ready," it says.