Berlin police on Saturday disbanded a mass protest in the German capital against coronavirus curbs a few hours after it had begun after marchers failed to keep their distance and wear masks as instructed.
The protest came as infections rise across Europe and as public frustration at measures to contain the virus grows in some quarters.
Similar events took place in Paris, London and elsewhere on Saturday.
"Unfortunately, we have no other option," Berlin police said on Twitter, adding people had failed to comply with the safety conditions of the march.
Protesters were dispersing peacefully although there were some pockets of disturbance, such as a construction container fire and blocked roads, police said.
Some 3,000 officers had been deployed to control crowds estimated at 18,000.
Police had been preparing for possible violence as activists opposed to measures to contain the virus urged social media followers across Europe to arm themselves and gather in Berlin.
Earlier this week the city banned the protest but a German regional court overnight gave the final go-ahead by overruling the earlier decision.
Until now Germany has managed the coronavirus crisis better than many of its European counterparts, with rigorous testing helping to hold down infections and deaths.
But new daily infections have accelerated in recent weeks, as in much of the world.
On Friday, Chancellor Angela Merkel urged citizens to keep up their guard against the virus.
"This is a serious matter, as serious as it's ever been, and you need to carry on taking it seriously," she said.
Protesters had gathered before the Brandenburg Gate in central Berlin ahead of the march with signs reading "Stop the corona lies" and "Merkel must go".
About two hundred anti-mask activists held a rally in Paris to protest against sanitary measures with slogans such as "No to the health dictatorship" and "Let our children breathe".
In London, several hundred demonstrators gathered in Trafalgar Square calling coronavirus a hoax and demanding an end to lockdown restrictions.
Many carried banners saying "Fake News," or "Masks are Muzzles" and rejecting any mandatory vaccination programmes.
The virus has killed more than 40,000 people in Britain.