Green Party MP and education minister Gustav Fridolin said he was “proud to be someone Nazis consider an enemy” after his speech was disrupted by the extremist group, reports news agency TT.
During Moderate Party and opposition leader Anna Kinberg Batra's speech, a group of NMR members shouted “treasonist” (“folkförrädare”), before gathering near the tent of newspaper Svenska Dagbladet, which was located close to the stage on which Batra spoke.
The Moderates leader said she “never” felt threatened during the disturbance.
“So many people were working to ensure security around me. And I never let things like this scare me, that would mean they have won,” Batra told Svenska Dagbladet.
Earlier, the Green Party's (Miljöpartiet) press meeting was also interrupted by NMR supporters shouting slogans.
“We were informed by telephone that a number of people were causing disturbances. Most moved on when we arrived but one person resisted and was arrested,” police spokesperson Carina Skagerlind told Aftonbladet.
Using a megaphone, the group called Fridolin and co-spokesperson Isabella Lövin “treasonists”, according to TT's report. The NMP supporters are reported to have been standing around 20 metres from where the press meeting was being held.
NMR confirmed on its website that one of its supporters had been arrested.
After police intervened in the disturbance one person became violent and was subsequently arrested for violent behaviour and attacking officers on duty.
Photo: Janerik Henriksson/TT
A further person was taken in for questioning on suspicion of interfering with a legal gathering.
Both individuals have subsequently been released but remain under suspicion, according to TT.
On Friday, a diversity demonstration was held in Visby in protest against the neo-Nazi movement's presence at the Almedalen politics festival.
Several hundred protesters waving rainbow flags took part in the diversity parade in Visby on the island of Gotland, where the annual Almedalen politics week is held.
Prime Minister Stefan Löfven, who is not present at the event, told TT that he is not happy with how Almedalen Week has changed.
The PM's decision to go on a tour of Sweden instead of appearing at the 7,000-participant Almedalen has attracted significant attention in Swedish media.
Löfven said that consultants and “other strong forces” had seen the event, which started in the 1960s, take a direction away from its original form as a people's movement.
He remained uncommitted as to whether he would take part in Almedalen 2018, with Sweden set to go the polls in a general election later that year.
“We'll make that decision next year. But I think that Almedalen needs to develop more as a people's movement. That's what it was before, that's Almedalen's tradition,” he told TT.
Police in Gotland will re-evaluate criteria for renting land during future editions of the Almedalen forum in order to prevent anti-democratic and violent messages, reports the news agency.