Swedish police have made three arrests following reports that scores of black-clad men targeted foreigners as they rampaged through central Stockholm on Friday.
Local media reported on Saturday that up to 100 men had attacked people and handed out leaflets threatening violence against foreigners, highlighting growing tensions in a country of 10 million people that received 163,000 asylum seekers last year.
Friday night’s incident was followed by an anti-refugee protest on Saturday, which resulted in some scuffles with counter-demonstrators, according to local media.
"Racist groups are spreading hate and violence in our streets. This has to be met with force," Interior Minister Anders Ygeman said in a statement on Saturday.
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Swedish newspapers said that according to witnesses a number of people had been attacked by the gang on Friday, who they reported were hooligans associated with local football teams.
One witness told the Aftonbladet newspaper that he had seen a group of men beating people in the middle of the capital's busy central Sergels torg square.
Police said three arrests were made on Saturday, the Reuters news agency reported.
The police also said one man had been arrested on Friday night for punching a plain clothes officer and another for carrying a knuckleduster, but the extent of assaults on immigrants was not clear.
Friday's incident came a day after a 22-year-old female worker was stabbed to death in a centre for unaccompanied asylum-seeking minors in the southwest of the country.
The leaflets handed out on Friday, which police said were also posted to Swedish social media, said: "When Swedish streets are no longer safe for ordinary Swedes it is our DUTY to fix the problem ... The police have amply shown that it lacks the means to rein them in and we now see no alternative than for us to mete out the punishment they deserve."
The Swedish government said this week it was likely to deport between 60,000 and 80,000 of last year's applications for refugee status in a move that drew criticism from rights groups.
More than 35,000 unaccompanied minors sought asylum in Sweden last year, roughly half of them registered as 16 or 17 years old. More than 23,000 of them came from Afghanistan.