Nineteen people were arrested in an operation costing up to £500,000
Nineteen people were arrested during a protest by about 1,500 people against the BNP's 10th annual Red, White and Blue festival in Derbyshire.
The march in and around Codnor passed off mostly peacefully, police said.
But some protesters threw bags of flour, eggs and fruit at officers as a few people tried to force their way through a police cordon.
More than 500 officers were deployed, while the demonstration was watched by an aerial camera mounted on a drone.
The police operation is expected to cost some £500,000.
A police spokesman said officers had to act after some protesters blocked or tried to block roads.
Demonstrators from United Against Fascism joined forces with the TUC and Amber Valley Campaign against Racism.
A letter condemning the event was published on Friday on United Against Fascism's website, with signatories including former London Mayor Ken Livingstone and children's author Michael Rosen.
The letter 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."
BNP deputy leader Simon Darby estimated that about 100 of those visiting the festival had been delayed by the protest march.
He added: "Local people wouldn't even know we were here if they didn't protest.
"We are just ordinary people having a bit of a laugh in the sun."
Derbyshire's Acting Assistant Chief Constable Steve Cotterill said: "We have made fewer arrests than we did last year and these arrests were for sporadic behaviour.
"Only when necessary was force used to keep order and maintain the rights of all who were present on the day.
"At no stage was it necessary to deploy officers in full riot gear."
At last year's BNP event more than 30 protesters were arrested, although no-one was charged with an offence.