Thousands of demonstrators gathered in the eastern German city of Erfurt on Saturday to protest the federal congress of the far-right Alternative for Germany (AfD) party, with tensions flaring as police confronted protesters attempting to disrupt the event.

Police estimated that around 20,000 people took part in demonstrations across the city ahead of the party's biennial congress. Protesters blocked roads leading to the venue and staged sit-ins in an effort to prevent delegates from reaching the congress hall.

Some demonstrators suspended themselves from a motorway bridge, while others glued themselves to tram tracks, causing transport disruptions. Thousands of police officers were deployed to maintain security, and sporadic scuffles broke out as officers removed protesters from blocked routes.

Authorities said the demonstrations were largely peaceful despite isolated incidents. Police recorded around 100 suspected offences, most of them involving property damage such as graffiti.

An AfD spokesperson said about 540 of the party's 600 delegates had reached the venue by early morning, allowing the congress to begin on schedule despite the protests.

Delegates are expected to re-elect co-leaders Alice Weidel and Tino Chrupalla as the party prepares for upcoming state elections, where AfD is seeking to strengthen its electoral position.

The timing of the congress has also drawn criticism, as it coincides with the 100th anniversary of the 1926 Nazi Party congress held in nearby Weimar. Historians and several politicians have questioned the symbolism of the date, while AfD has rejected the criticism, arguing that it is politically motivated.

Among those joining the demonstrations were Federal Environment Minister Carsten Schneider and Thuringia Interior Minister Georg Maier. Protest marches organised by civil society groups featured chants opposing the AfD and its policies.

Opening the congress, AfD co-chair Tino Chrupalla defended the party's right to hold its meeting, describing the protests as an attempt to undermine democratic decision-making. He also urged supporters to back the party in the upcoming state elections. (ILKHA)