The Iranian consulate in Germany was damaged on Sunday during a demonstration by regime critics who had gathered in the city of Frankfurt, dpa reported.
Protesters smashed a window and tore shutters off the building, police said.
Between 50 and 100 people had gathered in front of the building, officers added. They later planned to march on the offices of the public broadcaster for the state of Hesse, where Frankfurt is located.
The protest came as one person was killed in the Iranian capital Tehran during a police crackdown on anti-regime demonstrators earlier Sunday.