British Prime Minister David Cameron has condemned violence that erupted during a demonstration against government plans to triple university fees, and police admit they were unprepared.
Cameron says the actions of protesters who stormed a building housing the headquarters of his Conservative Party were "not acceptable and I hope that the full force of the law will be used."
Metropolitan Police chief Paul Stephenson said his force's failure to anticipate violence was "an embarrassment."
Demonstrators scuffled with police on Wednesday outside Conservative headquarters and dozens stormed the lobby, scattering furniture, spraying graffiti and chanting.
Fourteen people were treated for minor injuries and there were 35 arrests.