Iran’s exiled crown prince Reza Pahlavi was splattered with red liquid on Thursday as he left a building in Berlin.

Pahlavi had just departed a news briefing, during which he criticised the ceasefire between the United States and Iran, when the incident occurred outside Germany’s federal press conference building.

He appeared unhurt by the liquid coating the back of his blazer and neck, and waved to his supporters before he got into a car that drove away. Police said the liquid appeared to be tomato juice.

The alleged perpetrator, whose name was not released in line with German privacy rules, was immediately detained by police.

Pahlavi, 65, is the son of Iran’s former shah, who was so widely hated that millions took to the streets in 1979 to force him from power. Nevertheless, Pahlavi is trying to position himself as a player in his country’s future, though it’s unclear how much support he has in Iran after he has been in exile for nearly 50 years.

Hundreds of his supporters demonstrated Thursday near Germany’s parliament building, according to German news agency dpa.