Five men were arrested today over their alleged role in protests outside the Danish Embassy in London last month against cartoons satirising the Prophet Muhammad.
Four of the five were held on suspicion of incitement to murder and all five are suspected of "using threatening words or written material to stir up racial hatred".
During the demonstrations in Central London on February 3 and 4, protesters held placards threatening a repeat of the September 11 or July 7 terror attacks. Among the slogans were "Massacre those who insult Islam" and "Europe you will pay, your 9/11 will come".
The demonstration attracted widespread political condemnation and among those calling for prosecutions was the Muslim Council of Britain.
The Metropolitan Police said today: "A number of specialist evidence gathering officers were deployed who collected video, audio and stills of those within the crowd. A dedicated investigation team, Operation Laverda, was set up that day.
"After carefully reviewing all of the evidence and witness complaints a file was passed to the Crown Prosecution. Their advice was returned to us on 7/03/06."
Four of the men arrested today were held in London and one in the West Midlands. The four men in London have been taken to a Central London police station while the fifth is being questioned at a police station in the West Midlands.
Twelve cartoons caricaturing the Prophet Muhammad were first published in a Danish newspaper last September. Republication of the images in European newspapers provoked violent protests around the Islamic world.