Nine of the men have been prosecuted for violent riot and are accused of using shields to push journalists against a police vehicle and to hit police officers, while all but one were charged with agitation against an ethnic group. The demonstrators are also accused of throwing objects at police officers.

All of those involved have denied the crimes.

The protest in September last year in Gothenburg led to hours of unrest. Several hundred NMR supporters began the march along the route for which authorities had issued permission, but several protesters tried to break out of the designated area near the Svenska Mässan conference centre, which was hosting its annual Book Fair the same day.

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A 29-year-old acted as ringleader of the violence by the group, according to district prosecutor Jonas Martinsson.

“Of course it is serious when you attack the police during a demonstration,” he said. 

The charges of agitation against an ethnic group related to alleged messages spread by protesters about race, skin colour and origin.

Several of the NMR demonstrators carried posters labelling well-known Swedes, many of them of Jewish descent, as criminals. One of the men held a speech saying those featured on the posters were guilty of treason due to “mass immigration”.

According to the prosecutors, the demonstrators gave a “military impression” by wearing helmets and uniform-like clothes featuring the symbol of the NMR movement, as well as carrying shields.

“It is associated with the national socialism of the '30s and '40s, in my opinion,” said Martinsson.

During the press conference outlining the charges, police assistant Stefan Claesson said that the investigation of the suspected crimes had included looking through “an emormous [range of] material” including films.

Much of the evidence came from body cameras worn by police during the event, and both police officers and journalists will also testify as witnesses in court.

The prosecutor did not state the penalty he would be asking for, and it has not yet been decided when the trial will be held.