Four protesters were detained at the Tower of London on Saturday for smearing the display with the state crown with food products, LETA reports citing DPA.
The responsibility for the action was claimed by a little-known organization Take Back Power, describing itself as a non-violent civil resistance movement.
The display containing the state crown was smeared with custard and apple dessert.
"The UK is broken. We came here, to the national treasures, to take back our power," said one of the protesters in a video posted online, calling for others to join the movement.
While the police conducted an investigation, the Tower's Jewel House was closed to visitors.
The organization Take Back Power stated that it held the action to demand the government establish a permanent assembly of citizens — a People's Chamber — which would be empowered to "tax excessive wealth and rectify the situation in the UK."
