At least 24 people from Germany's right-wing scene were arrested in the eastern city of Leipzig on Saturday during a protest against coronavirus measures.
Police, who had prepared for a large-scale operation, said those arrested had been carrying prohibited objects.
"They can no longer participate in any event today," authorities said.
"Our ultimate goal is that there is no march," police spokesman Olaf Hoppe added.
More than 1,000 people turned up for the protest staged by the so-called Leipzig Movement. A demonstration against mandatory vaccination was also planned.
COVID rules restrict protest
Initially, the Leipzig Movement had registered 3,000 participants who were supposed to march across the Leipzig Ring, the city's inner ring road.
But due to tightened coronavirus restrictions in the state of Saxony, of which Leipzig is the largest city, only stationary demonstrations with a maximum of 1,000 participants are authorized.
Already by early afternoon, the place of assembly was cordoned off because the maximum number of protesters had been reached.
Numerous people also gathered for a counter-protest in the city.
Last November, some 20,000 people took to the streets in Leipzig for a similar rally staged by the Querdenken (Lateral Thinking) movement that turned violent.
The Querdenken movement, which is made up of coronavirus deniers, right-wing activists and anti-vaccination campaigners, has held several large-scale demonstrations during the pandemic.
German intelligence warns COVID deniers increasingly radical
Ahead of Saturday's protest, Stephan Kramer, the head of the domestic intelligence agency in the eastern state of Thuringia, warned of increasing radicalization among coronavirus deniers.
"The fourth wave, the discussion about booster vaccinations and tightening of coronavirus measures such as the extension of proof of vaccination or recovery regulations can lead to a new impetus for the scene," Kramer told the Redaktionsnetzwerk Deutschland news group.
"We are experiencing online bullying, insults, physical attacks and ultra-aggressive behavior all over the country," he said.
This is now the order of the day across the country, he added. The fourth wave of the pandemic as well as "communication deficits and contradictions in politics, for example regarding booster vaccinations" are prompting the scene to feel validated and "further fueled," Kramer said.
Saxony to implement 2G rule
Saxony will be the first federal state to implement the so-called "2G" rule compulsorily in parts of public life from Monday. In Germany, the 2G rule means people must be fully vaccinated against COVID or have recovered from it in order to access indoor dining and other indoor events.
The eastern state has the highest incidence rate in Germany at 415.8 new infections per 100,000 people over the past seven days.
According to the Robert Koch Institute for infectious diseases, Saxony also has the lowest vaccination rate, with just 57% of its inhabitants fully inoculated, compared with the national average of 67%.
mvb/nm (dpa, AFP, Reuters)