A Home Office minister has warned those planning far-right protests this weekend that police are watching them.
Demonstrations are expected in cities across the country, from Glasgow to Dover, following violent unrest around the Southport stabbing attack.
Hundreds of mosques are strengthening security amid concern Islamic places of worship could be targeted.
Lord David Hanson said police are monitoring organisers and would be using facial recognition technology to identify people.
More than 100 people have been arrested at demonstrations after violent disorder was sparked by the murder of three primary school age girls at a dance studio on Monday.
The BBC has identified at least 30 additional demonstrations being planned by far-right activists around the UK, including a new protest in Southport, this weekend.
“Nobody minds peaceful protest,” Home Office minister Lord Hanson told BBC Breakfast.
“But what happened this week in Southport, and what’s happened elsewhere in the country, is organised individuals who have undertaken criminal activity to intimidate, to attack police, to break personal property, and that’s not acceptable.”
Highlighting how conspiracy to organise a riot is an offence, he added “we are reminding people who are going to potentially commit this crime that we are watching them through intelligence-led policing”.
Asked about the possibility of violent protests this weekend, he told LBC: “There is that potential.
“But I always say to anybody who’s organising this, we will be watching you. If you are organising this now, we will be watching you.
“We have powers under existing legislation to stop you organising this now and to take action accordingly, and if you do take action and are not part of any organised group, be prepared to face the full force of the law on this criminal activity.”
Security staff are being hired at mosques in cities across the UK due to phoned-in threats about “targeted attacks”, the Muslim Council of Britain (MCB) reported.
There is “deep-seated anxiety” and “palpable fear” among communities, MCB secretary-general Zara Mohammed said, urging mosques to work closely with police.
Ms Mohammed said: “We go by what we’ve seen already and from what online posters are saying, but it sounds like far-right thugs and mobs are going to seek to intimidate congregations and mosques.
“In Southport they were pelting stones and glass bottles, shouting Islamophobic slurs and abuse.
“So it’s likely that we may again see groups of men and thugs coming together outside of the mosques to intimidate.”
Protests are understood to be planned for areas such as Liverpool, Glasgow, Lancaster, Blackburn, Newcastle, Birmingham, Sunderland, Dover, Middlesborough, Leeds and Hull, the MCB said.
Lord Walney, the UK Government’s adviser on political violence and disruption, said there was a “concerted and co-ordinated” attempt to spread disorder and police had the powers to “step in” and prevent violence.
“Clearly, some of those far-right actors have got a taste for this and are trying to provoke similar in towns and cities across the UK,” he told the BBC’s Good Morning Scotland.
“Where there is these kinds of gatherings which are just designed to be fanning the flames of violence, (the police) should be stopping people gathering.
“People absolutely have the right to protest in this country, but they do not have the right to riot.”
Civil rights campaign Big Brother Watch has expressed concern about the use of facial recognition technology, which the group’s director Silkie Carlo described as “alarming” for democracy.
“Whilst common in Russia and China, live facial recognition is banned in Europe,” she said.
“This AI surveillance turns members of the public into walking ID cards, is dangerously inaccurate and has no explicit legal basis in the UK.”
