Alternative for Germany came second in the European Parliament elections earlier this month.
Massive protests have erupted as the far-right Alternative for Germany (AfD) party opened its convention in the western city of Essen, with demonstrators attempting to block roads and clashing with police.
Police used pepper spray and batons on Saturday to push back protesters who tried to break through a cordon before the two-day event began, a police spokesman told German news agency dpa.
According to police, masked protesters attacked officers. Around 1,000 police officers have been deployed in Essen.
“Several disturbing violent actions occurred… protesters, some of them hooded, attacked security forces. Several arrests were made,” the police of the state of North Rhine-Westphalia, where Essen is located, reported in X.
German police later said two officers were seriously injured during the clashes.
“Unknown assailants kicked the two police officers in the head” and continued to beat them even when they were on the ground, police said. Both men were hospitalized with serious injuries, according to a statement.
Up to 100,000 protesters are expected to take part in counter-demonstrations and other events in Essen, dpa reports. Authorities have expressed concern that while the majority may be peaceful, around 1,000 leftists would use violence to disrupt the congress.
Left-wing groups warned that they could block the entrances to the venue to prevent the entry of AfD delegates.
Some 600 delegates are gathering, and the party's current co-leaders, Alice Weidel and Tino Chrupalla, will seek re-election ahead of Germany's parliamentary elections next year.
Weidel told delegates as he opened the meeting that “what is happening out there has nothing to do with democracy,” adding that “we are here and we will stay.”
“We have the right, like all political parties, to hold a congress,” he added.
The AfD won 16 percent of the vote and finished second in European Parliament elections earlier this month, despite a series of scandals and setbacks.
The party was expelled from the Identity and Democracy (ID) group in the European Parliament in May following comments by its leading candidate, Maximilian Krah, to an Italian newspaper that members of the Nazi paramilitary SS force “were not all criminals”.
While AfD banned Krah from campaigning, the party was already under scrutiny over allegations that it harbours agents for Russia and China. One of its aides was arrested on suspicion of spying for China.