Five men have been arrested over their alleged role in protests against cartoons satirising the Prophet Muhammad, Scotland Yard said.
Police made no arrests during the protests in London
The five were alleged to have taken part in the 3 February demonstration which took place in London.
Four of them were held at their London homes in Tower Hamlets, Waltham Forest, Redbridge and Southall and were taken to a police station for questioning.
A fifth man, who is from Birmingham, is being questioned in the West Midlands.
Last week police said arrests would be made "in the near future" over the protests outside the Danish Embassy on 3 and 4 February.
Placards were seen which appeared to threaten a repeat of the 11 September attacks or the 7 July London bombings.
The Crown Prosecution Service said there were grounds for arrests on suspicion of public order offences.
Officers subsequently examined 60 hours of video from CCTV cameras and evidence-gathering teams deployed at the protests.
Scotland Yard received more than 500 complaints from members of the public about the demonstrations.
Shadow home secretary David Davis was among those calling for action, and he wrote to the Home Secretary Charles Clarke attacking the "unconscionable" delay in making arrests.
The cartoons, which were originally published in a Danish newspaper, sparked worldwide protests.
Among the images which have sparked outcry is one of Muhammad with a bomb-shaped turban on his head.
Newspapers in Spain, Italy, Germany and France were among those to reprint the material.