Alice Weidel condemned the protesters outside / © AFP
The far-right Alternative for Germany (AfD) founded its new youth wing "Generation Deutschland" on Saturday in the face of noisy protests that delayed its meeting by more than two hours.
According to police, at least 25,000 protesters descended on the central town of Giessen near Frankfurt to oppose the AfD event.
The meeting had been due to start at 10:00 am local time (0900 GMT) but only got underway after noon, accompanied by audible whistles, drums and chants from the protesters outside.
The party's co-leader Alice Weidel condemned those who had caused "chaos" outside and said those gathered in the hall were "the new generations of the party".
The anti-immigration AfD became Germany's main opposition at February's general election, in which it won a record score of more than 20 percent, and hopes to make further gains at state elections next year in its eastern heartlands.
The new youth organisation will replace the Junge Alternative (JA), which was classified as an extremist group by intelligence services and then disbanded by the AfD earlier this year, pre-empting a possible ban.
The JA had frequently been involved in controversies, including its members using racist chants and holding meetings with neo-Nazis.
The party's other co-leader Tino Chrupalla admitted in his speech to the hall that the party had "to learn from past mistakes".
Some of those active in the party's previous youth activities had "banged their heads against the wall rather than getting their foot in the door", he said.
- 'A new Hitler Youth' -
Generation Deutschland's first leader will be Jean-Pascal Hohm, 28, an AfD state lawmaker from eastern Germany with long-standing ties to various far-right and ethno-nationalist groups.
He was elected leader by an overwhelming majority, with attendees rising from their seats to applaud him and shout his name.
Thousands of anti-AfD protesters gathered from the early morning / © AFP
In his speech to the hall he promised to "fight for a real change in migration policy so that Germany remains the homeland of Germans".
Christopher Tamm, a 25 student and local AfD politician from the eastern state of Brandenburg, said he was "very happy" with how the afternoon went.
Hohm "has all the necessary knowledge and skills" to lead the organisation, Tamm told AFP.
Inside the hall, stalls were set up offering the attendees -- overwhelmingly men -- merchandise including protein powder and mugs and T-shirts bearing images of AfD leaders.
Outside there were some clashes between police and protesters seeking to block access to the AfD meeting, with police saying several officers were lightly injured.
Other demonstrators flew rainbow flags and held up banners with anti-AfD slogans.
Carsten Kachelmus, a 52-year-old who works in programme management, told AFP: "We mustn't allow a new Hitler Youth to be created, especially us with our history here in Germany."
"That's why it's so important for us to show solidarity and to resist."
- 'Far-right milieu' -
In May, Germany's domestic security service declared the AfD as a whole a "right-wing extremist" organisation, fuelling calls to ban it.
The party has challenged the designation in the courts.
Jean-Pascal Hohm is considered to be from the radical wing of the AfD / © AFP
Political observers expect Generation Deutschland to be at least as radical as the JA.
Fabian Virchow, of the University of Duesseldorf, said that "the leading figures come from a far-right milieu, in which former activists from the Identitarian Movement, fraternities, neo-Nazism and ethno-nationalist groups come together".
While the JA operated as a registered association relatively free of the parent party, its successor is set to be more closely integrated into the AfD and subject to its disciplinary structures.
Stefan Marschall, of Heinrich Heine University in Duesseldorf, said the new set-up "gives the party leadership control over this branch of the organisation and thus helps it to present a more unified front.
"However, this comes at the cost of the party no longer being able to completely credibly distance itself from the youth organisation should it adopt problematic positions."
