Around 1,500 anti-fascist demonstrators from across Britain joined a protest march to voice their opposition to an annual festival organised by the BNP.
The march in and near the Derbyshire village of Codnor passed off largely peacefully, although a handful of arrests were made as protesters attempted to break through a police cordon.
At least four men were led away in handcuffs after scuffles broke out and missiles, including bags of flour, plastic bottles, eggs and fruit were thrown at police.
The sporadic disorder occurred as some of those at the head of the march tried to force their way past a designated protest area.
Officers had earlier made a small number of other arrests after protesters acted unlawfully near the site of the BNP's annual Red, White and Blue Festival, a Derbyshire Police spokesman said.
The main body of demonstrators, which was monitored by a camera mounted on a drone, gathered in Codnor's Market Place, chanting "Nazi scum, off our streets" and waving placards from campaign group Unite Against Fascism and various trade union groups.
The march came a day after an open letter was published on Unite Against Fascism's website, condemning the BNP event.
The letter, whose signatories include former London mayor Ken Livingstone, children's author Michael Rosen and trade union leaders, accused the BNP of trying to "build up a hardened neo-Nazi core at the centre of the organisation".
It said: "We condemn the BNP and its festival of race hate, and we urge people to reject this party's poisonous and anti-democratic agenda."
This year was not the first time the festival attracted opposition. Last year, around 30 anti-BNP protesters were arrested after clashes with police.