Climate activists have spray-painted parts of the Brandenburg Gate in central Berlin with orange and red paint.
At least 13 people have been arrested, suspected of vandalism, the police told local media.
Behind the action is the group Letzte generation (Last generation), which in recent years has attracted attention with various kinds of actions. Pictures on social media show them using fire extinguishers to paint the monument.
On X, formerly Twitter, the group writes that it intends to continue protesting until the politicians decide to end dependence on fossil fuels by 2030.
They justify the action at the Brandenburg Gate with the fact that the place is a symbol of “great and hopeful turning points in German history”.
They have also announced more actions in Berlin and the rest of Germany in the coming weeks, including blocking roads in protest against politicians’ non-action on the climate issue.
Several of the group’s members were put on trial this spring, including after blocking traffic by gluing themselves to roads in Germany. In several other cases, activists have, for example, gone on hunger strike and vandalized art in museums.