Police forces take protesters into custody during a demonstration against a party congress of the German right wing party AfD.

Story highlights

More than 1,000 people were protesting outside a far-right political party in Stuttgart

Demonstrators tried to block entrances and things got violent, police said

CNN  — 

Five hundred people were arrested in Germany after violent clashes broke out, authorities said.

More than 1,000 people were protesting Saturday in Stuttgart, where Alternative for Germany, a far-right political party, is holding a two-day conference over the weekend.

Demonstrators tried to block party members from entering the building where their conference was taking place.

Opinion: Merkel down but not out

Protesters then clashed with police, throwing flares and setting tires on fire, according to Richard Leuze, the spokesman for Reutlingen police.

About 2,000 party members were trying to attend the conference.

Another smaller, peaceful demonstration in the southern German city drew about 800 people.

Police clash with protestors angry about Cologne sex attacks

More protests are expected Sunday during the convention’s second day.

CNN’s Joshua Berlinger contributed to this report