Two people were arrested for public order offences during the Prime Minister's visit to Edinburgh, police said.
A 22-year-old man and 19-year-old girl were arrested in the Grassmarket area of Edinburgh while David Cameron met First Minister Alex Salmond to discuss plans for an independence referendum.
A spokesman for Lothian and Borders Police said there were "appropriate resources in place" for demonstrators in the Grassmarket but said some "chose not to take advantage of it".
The man and woman will remain in police custody ahead of an appearance at Edinburgh Sheriff Court.