Two police officers were hospitalised Saturday after clashes with hooded protesters outside the congress of Germany's far-right AfD, as the party met weeks after its record EU election result.
About 1,000 police were deployed in the western city of Essen, where demonstration organisers said 50,000 protestors marched towards the congress. The police have not yet provided figures.
"We want to govern, first in the east (of Germany), then in the west, then at federal level," Tino Chrupalla, co-president of the Alternative for Germany (AfD), told around 600 delegates of the two-day meeting which start half an hour late due to street blockades.
Police said two officers, a man and a woman, had to be hospitalised following attacks by protestors.
"Unknown assailants kicked two police officers in the head" and continued to "hit them while they were on the ground", said the police of North Westphalia, where Essen is located.
Doctors later established their injuries were not as serious as initially feared, said police.
Seven officers were also slightly injured in the clashes near the Grugahalle hall. The perpetrators fled the scene.
Police said earlier they had used pepper spray and batons in earlier clashes.
"Several disruptive violent actions occurred in the Ruettenscheld quarter. Demonstrators, some of them hooded, attacked security forces. Several arrests were made," the police of North Westphalia, where Essen is located, said on X, formerly Twitter.
A top regional official had warned that "potentially violent far-left troublemakers" could be among the protesters.
The total number of officers injured Saturday was 28, said police, adding that several people had been arrested.
In early June the Alternative for Germany (AfD) notched up its best European Union election result since its creation in 2013, winning 16 percent of the vote to take second place.
Chrupalla praised party progress at a local level and its strong European Union election result.
It was behind the main conservative CDU-CSU opposition bloc but ahead of Chancellor Olaf Scholz's Social Democrats (SPD), which is in power at the head of a troubled three-party coalition.
The AfD congress comes ahead of three key elections in September in states that once formed part of communist East Germany, and where the AfD has been topping opinion polls.
"We are here and we will stay," said party co-president Alice Weidel, opening the congress and drawing sustained applause.
Both Weidel and Chrupalla were re-elected to lead the party for another two years.
"We have the right like all political parties -- to hold a congress," she added.
Buoyed by a surge in immigration and a weak performance by Europe's top economy, the party hit as high as 22 percent in opinion polls in January.
However their support faltered amid a welter of scandals that mainly implicated their top EU election candidate, Maximilian Krah.
"I believe that the party has learnt a lot in recent months and will be very careful when we put forward leading candidates in the future," Weidel told the Politico news outlet Thursday.
Krah initially faced allegations of suspicious links to Russia and China.
He then sparked widespread anger by telling an Italian newspaper that not every member of the Nazis' notorious SS was "automatically a criminal".
The comments prompted the AfD's expulsion from its far-right group, Identity and Democracy (ID), in the European Parliament, in which France's National Rally (RN) and Italy's League had been its partners.
While the AfD has sought to shift the blame for all its recent woes onto Krah, there were signs of problems even before.
The RN had already distanced itself from the AfD after reports emerged in January that the German party had discussed the expulsion of immigrants and "non-assimilated" citizens at a meeting with extremists.
The reports caused shock in Germany and triggered weeks of mass protests.
Following the EU polls, the AfD ejected Krah from the delegation it sends to Brussels but the ID group does not seem ready to re-admit them, leaving the party searching for new partners.