Muslim Cleric Abu Hamza al Masri lost his appeal to remain in the UK and will be extradited to the US immediately.
Outside London's high court, his supporters held protests which soon turned into scuffles.
The cleric argued in his appeal that he could face inhumane treatment in the U.S.
Washington says he supported al Qaeda , plotted a kidnapping in Yemen and tried to open a training camp for militants.
Abu Hamza, who has spent the past seven years in prison in the UK, could be sent to a Supermax prison in the U.S. with a sentence of more than 100 years.
