Far-right activist Tommy Robinson is among those tapping into a "sense of disquiet" in the country, a Cabinet minister has told the BBC, after thousands joined a march and counter-protest in London on Saturday.
Business Secretary Peter Kyle said marchers were demonstrating freedom of association and freedom of speech, after up to 150,000 joined a "Unite the Kingdom" rally, organised by Robinson and about 5,000 took part in a counter-protest, co-ordinated by Stand Up To Racism.
But he told Sunday with Laura Kuenssberg the "small minority" who had committed violence would be held accountable.
Twenty-six police officers were injured, the police said, and 24 people arrested for a range of offences.
Kyle criticised Elon Musk's comments after he appeared at Saturday's rally via video link telling protesters to "fight back" or "die".
