Hundreds of anti-fascist activists have protested outside the BBC Television Centre in London against the leader of the British National Party who was appearing in a political debate.
About 25 people were thrown out by police after breaking through a gate at the building.
BNP leader Nick Griffin was appearing on the BBC's flagship programme, Question Time.
He described the protesters as disgraceful, saying they were "attacking the rights of millions of people to listen to what he has to say and see him being called to account.
BBC deputy director general Mark Byford says Mr Griffin's participation in the programme was part of the BBC's "responsibility of due impartiality".
Critics say Mr Griffin's appearance will legitimise the BNP and promote violence against ethnic minorities.