Dutch police used tear gas and water cannon to disperse violent anti-immigration protesters in The Hague on Saturday.
Thirty people were arrested and two officers injured as large groups clashed with police, some throwing rocks and bottles.
Around 1,500 people blocked a highway crossing the city, while a police car was set on fire, according to the Netherlands news agency ANP, citing police figures.
Prime Minister Dick Schoof condemned the shocking and bizarre images of shameless violence, stating it was completely unacceptable.
Right-wing leader Geert Wilders, who won the previous election and retains a lead in opinion polls ahead of a 29 October vote, was invited to speak at the demonstration but did not attend. He also condemned the violence against police as utterly unacceptable, attributing it to idiots.
The protest was organized by a right-wing activist calling for stricter migration policies and a clampdown on asylum seekers.
Violence erupted when large groups of protesters, many waving Dutch flags and flags associated with far-right groups, confronted security forces.
Protesters also vandalized the headquarters of the D66 party, viewed by many on the far right as serving a progressive elite. D66 leader Rob Jetten reported extensive damage inside, urging protesters to stay away from political parties and stating that intimidation will not deter their resolve.
The Dutch government collapsed in June after Wilders withdrew his far-right PVV party from the governing coalition following a dispute over migration policies, including a freeze on asylum applications and limiting family reunification.