Ringleaders plotting more violent demonstrations in Britain were warned by the Government “we are watching you” as it sought to stop the “summer madness” from spreading.
Home Office minister Lord Hanson stressed the police would be seeking to track individuals involved in conspiring to encourage violent protests.
He also told people considering taking part in violent incidents, after the Southport stabbings, that they should be prepared to end up in court and possibly go to jail.
After a series of outbreaks of violence, he told LBC Radio: “We want to send a signal to those people who are potentially undertaking conspiracy that they know that we will use intelligence-led policing, we will use all the tools available to make sure that we prevent this activity if at all possible and if it does happen that they need to know that they will face the full force of the law.
“This is not about peaceful protest, this is about criminal activity.”
He admitted there was the “potential” for more violence this weekend.
However, raising the prospect of arrests of ringleaders, he added: “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.”
Pressed if the violent protestors were far-Right, he added: “Some individuals will have far-Right opinions, some might be caught up in the summer madness, some might be people who have got genuine concerns.”
He backed the right to demonstrate peacefully and raise issues with MPs.
“What they can’t do is throw rocks at police officers, break window in mosques and attack people in the street and undertake street robbery as has happened to some of the shops in Southport,” he added.
“That is simply not acceptable.”
He stressed: “The key message I want to put to people is just simply this.
“If you are thinking of taking action along the lines of has happened in Southport this week, do not do it because you will face the full force of the law, through the police and through the courts in due course.”
More than a dozen protests have been planned for the coming days in the wake of the Southport stabbings, as Sir Keir Starmer announced a new “national” response to the violent disorder linking police forces across the country.
He also slammed thugs for a “Nazi salute at the Cenotaph” and firing flares at the statue of Winston Churchill in Parliament Square during a demonstration on Wednesday.
At least 15 more protests were being advertised online, some calling for participants to bring England flags and a number contain phrases such as “enough is enough”, “save our kids” or “stop the boats”.
The protests are being planned for areas such as Southport, Leeds and Bristol, as well as the London commuter belt town of High Wycombe.
Emma Reynolds, Labour MP for Wycombe, tweeted: “I have raisedconcerned with the Thames Valley Police about the planned potential civilunrest by the far right tomorrow (Saturday) in High Wycombe.
“It is unacceptable that they’re trying to exploit thehorrific murders in Southport to stoke division and target communities.”
Two counter-protests in the country are also being advertised online.
It comes after the 17-year-old charged with the murder of three girls in the knife attack at a Taylor Swift-themed dance class appeared at Liverpool Crown Court and was named as Axel Rudakubana, from Banks in Lancashire.
The defendant is charged with the murder of Alice Dasilva Aguiar, nine, Bebe King, six, and Elsie Dot Stancombe, seven, in Southport on Monday.
He is also charged with the attempted murder of yoga class instructor Leanne Lucas, businessman John Hayes and eight children, who cannot be named for legal reasons, as well as with possession of a kitchen knife with a curved blade.
He was remanded to youth detention accommodation and will next appear in court in October.
The alleged attack, which happened at a dance class on Hart Street in Southport just before midday on Monday, has sparked incidents of violent disorder in some towns in England.
Thousands of people turned out to pay their respects to the victims at a vigil in Southport on Tuesday evening, but violence later erupted outside a mosque in the town with 53 police officers and three police dogs injured.
On Wednesday evening, more than 100 protesters were arrested on Whitehall, where bottles and cans were thrown at police, and violence broke out in Hartlepool, County Durham.
Cleveland Police have so far made 12 arrests, one of which was an 11-year-old boy arrested on suspicion of arson after a police vehicle was set alight.
Police in Manchester confronted another demonstration outside the Holiday Inn on Oldham Road before dispersing the crowd after protesters started throwing beer bottles at officers and members of the public.
During a press conference on Thursday, Prime Minister Sir Keir Starmer condemned “Far-Right hatred” in the wake of the Southport stabbings as he announced a new “national” response to the violent disorder.
Sir Keir said: “The Far Right are showing who they are - we have to show who we are in response to that.”
The new “national capability” will involve sharing intelligence, wider deployment of facial recognition technology and criminal behaviour orders to restrict the movement of those involved, Sir Keir said.
The Prime Minister also sounded a note of caution to social media companies after misinformation spread online about the identity of the 17-year-old suspect, including false claims that he was an asylum seeker.
