SWEDISH riot police clashed with counterdemonstrators at a neonazi rally in Stockholm on Saturday.

Four police officers and three civilians were slightly injured in violence that erupted on the sidelines of a march by about 150 members of the far-right Party of the Swedes.

Thousands of people gathered in central Stockholm to protest peacefully against the march but a few dozen masked activists attacked police with fireworks, bottles, eggs and panels ripped from a security fence.

Police spokesman Lars Bystrom said that one person had been arrested for “preparation for aggravated assault,” while another was arrested for trespassing after climbing onto the roof of the Royal Opera, outside which the neonazis had started and ended their march.

Fifteen people were taken into custody for violating a ban on wearing masks at political demonstrations.

Police had sealed off large parts of central Stockholm because of the march by the Party of the Swedes, which calls for an end to immigration and demands that Swedish citizenship should be reserved for people with “Western genetic and cultural heritage.”

Formerly known as the National Socialist Front, the party won a local council seat in a small town in central Sweden in 2010. 

Polls before a coming September 14 election show it only has a fraction of the support needed to enter the national Parliament.

A week ago, three people were injured when mounted riot police charged demonstrators in the southern city of Malmo, in connection with another protest against the Party of the Swedes.