Swedish activists clashed with police amid a hail of bottles and fireworks in downtown Stockholm on Saturday as they tried to break through a police line and attack an anti-Islam demonstration.
Police spokesman Kjell Lendgren said around 400 leftists had gathered to heckle the 100-strong demonstration, which was rallying to bring attention to what it perceives is the Islamization of Europe.
He said the leftists shouted and blew vuvuzelas to drown out anti-Islam and nationalist speeches, but then started throwing bottles and lit fireworks at police, injuring two officers.
Lendgren said ten activists were arrested, after which the situation calmed down.
Both the anti-Islam meeting and leftist protest continued peacefully and were scheduled to end at 1600 local (1400GMT).
Activists used vuvuzelas (Photo: AFP)
The far-right rally was organized by groups including the English Defense League (EDL) which has been a driving force behind a handful of similar events, most recently a Danish rally in March.
The EDL gained international attention through anti-Islamic fanatic Anders Behring Breivik,
who killed 77 people in Norway a year ago and who referred to it admiringly in a manifesto on the Internet. The group has denied links to Breivik.
Support has grown in European countries for populist, nationalist and anti-immigration movements and in Sweden the anti-immigrant Sweden Democrats won seats in parliament for the first time in 2010.
However, previous attempts by European far-right groups to join forces have foundered amid splits and feuding over ideology and leadership.
Nottingham University's Matthew Goodwin, an expert on British far-right militant groups, said the Stockholm meeting was of strategic importance despite the modest turnout.
"The attending are quite significant figures within the anti-jihad movement. It signifies the strengthening links between counter-jihad groups and anti-Muslim groups within Europe and the United States," he said.
EDL leader Stephen Lennon, who also calls himself Tommy Robinson and who founded the group three years ago, said the meeting was about sharing resources and coordinating strategies.
"It's about sharing ideology, sharing resources, work together in any way we can over the next 12 months in order to highlight the truth, the truth about Islam," he told Reuters on the sidelines of the Stockholm rally.
Pamela Geller, a leader of groups Stop Islamization of Nations and Stop Islamization of America, said the movement was planning to hold a conference in New York on September 11.
"It's very important that it goes global because what we are fighting is a global ideology," she said.
AP and Reuters contributed to this report