Thousands of demonstrators crowded into Berlin's central Alexanderplatz square on Saturday to protest racism and police violence, with further rallies planned in 25 German cities.
Berlin police took to Twitter to ask protesters to stop arriving in the square, declaring it "full" 45 minutes after the anti-racism demonstration was due to begin.
Officers had earlier called on attendees to maintain physical distance from one another and wear masks to limit the spread of the coronavirus.
Police also asked protesters to spill over into adjacent streets to maintain safe distancing.
Just 1,500 participants were registered for Saturday's rally, though police were expecting up to 10,000 to attend.
Aerial photographs shared on social media showed large crowds dressed in black and carrying banners supporting the Black Lives Matter movement.
Organizers calling for "silent demos" across Germany paying tribute to George Floyd, an African-American man killed by a US police officer on May 25, have circulated online in recent days.
Police in the northern city of Hamburg said around 14,000 attended a number of rallies in the city centre there, while officers in the western city of Frankfurt said 8,000 protesters had gathered.
The killing has sparked nightly protests and riots across the United States, with Washington gearing up for renewed protests on Saturday.
