Thugs who cause criminal disorder on the streets will "pay the price", the government has said, amid warnings that more violence is likely in the coming days.
Clashes between anti-immigration protesters and counter-protesters took place in cities across England and Northern Ireland on Saturday, with police officers being attacked and injured and a number of arrests made, with many more expected.
The string of violent incidents in recent days began in Southport on Tuesday after three girls were killed in a knife attack at a Taylor Swift-themed holiday club.
Home Secretary Yvette Cooper said those involved in the clashes "will pay the price" and that "criminal violence and disorder have no place on Britain's streets".
Prime Minister Sir Keir Starmer said police have his "full support" in taking action against "extremists" who seek to "spread hatred" by intimidating communities, as he held emergency talks with ministers over the unrest in parts of England.
The far right was condemned by MPs from across the political spectrum after unrest broke out in London, Manchester, Southport and Hartlepool ahead of Saturday's violence.
Arrests have been made across the country and police warn more arrests will follow as CCTV, social media and bodycam footage is combed through.
Justice Minister Shabana Mahmood told ministers that "the entire justice system is ready to deliver convictions as quickly as possible", a Downing Street spokesman said. A report said it could mean courts sitting 24 hours a day, as they did during the 2011 riots.
On Saturday, violence broke out in cities including Hull, Liverpool, Stoke-on-Trent, Nottingham, Bristol, Manchester, Blackpool and Belfast, with several police officers injured.
This happened after a riot in Sunderland on Friday evening.
Culture Minister Lisa Nandy said anyone who attacks police "should be ashamed".
She wrote on X: "I can't thank our local police enough for everything they do to keep people safe.
They were among the first on the scene when the horrific incident unfolded in Southport.
They risk themselves to protect us, and those who attack them should be ashamed."
Northern Ireland must always be a place where the right to protest, the right to have an opinion and to express it, is protected.
Let us be VERY clear: violence is not acceptable. It never was and it is not now. No one, NO ONE, has the right to express hatred and violence. Stop it now.
- Emma Little-Pengelly BL (@little_pengelly) August 3, 2024
Emma Little-Pengelly, Deputy First Minister of Northern Ireland, said "violence is not acceptable".
"Northern Ireland must always be a place that protects the right to protest, the right to have an opinion and express it," she posted on X.
"Let's be VERY clear - violence is not acceptable. It never was and it is not now. No one, NO ONE, has the right to express hatred and violence. Stop it now."
In Liverpool, Merseyside Police reported that around 300 people were involved in violent disturbances on County Road, Walton, which included setting fire to community facilities.
The Spellow Lane Library Hub, which opened last year to provide a much-needed base for one of the most deprived communities in the country, has suffered severe damage to the ground floor.
According to police, rioters tried to block firefighters from reaching the fire, throwing a projectile at the fire truck and smashing the rear window of the cab.
A total of 23 people were arrested on Saturday, including 12 for the disturbances in the city centre, nine for the disturbances on County Road and two for the disturbances in Southport.
A police officer was kicked and pushed off his motorcycle by a protester, while others tried to kick shields.
A heavy and visible police presence remains in Hull city centre tonight as 20 arrests have now been made for various public order offences. ACC Mike Walker said: "Enforcement action will continue as we will not tolerate senseless violence and disorder in our city." More here: https://t.co/QA8xG8g3l4
- Humberside Police (@Humberbeat) August 3, 2024
In a post on X, Liverpool City Council urged people to "stay away" and let police "deal with this ongoing situation in Walton".
Deputy Chief Constable Alex Goss called the protesters' behaviour "reprehensible", adding: "The impact of the disorder will be devastating for the people of Walton but I promise we will do everything we can to arrest those involved and bring them to justice."
Merseyside Police also reported that a 58-year-old man has been charged with two offences following violent disorder in Southport on Tuesday.
Derek Drummond, of Pool Street, Southport, has been charged with violent disorder and assault on an emergency worker. He will appear at Wirral Magistrates Court on Monday, August 5, police said.
In Hull, 20 people were arrested, three police officers were injured and shops were looted and set on fire after a mob attacked a hotel housing asylum seekers, according to Humberside Police.
Deputy Chief Constable Mike Walker said: "The right to lawful protest is part of democracy and one that my officers have upheld. However, we will not accept the senseless vandalism, anti-social behaviour and sheer violence that has erupted on our streets."
Businesses in Belfast were targeted. Police carried out a large-scale security operation during a prolonged confrontation between anti-Muslim protesters and participants in an anti-racism demonstration at Belfast City Hall, during which fireworks and other missiles were thrown.
In Bristol, police have arrested 14 people over violent disorder in the city centre, which Avon and Somerset Police described as "completely unacceptable".
Lancashire Police said more than 20 people have been arrested and dispersal orders have been issued to disperse the group in parts of Blackpool, Preston and Blackburn.
Ten people have also been arrested following the disturbances in Stoke-on-Trent, according to Staffordshire Police.
According to police, more protests are planned for Sunday and it is likely that more trouble will arise in the coming days.
"We know people will try this again and the police are and remain prepared," said Chief Constable BJ Harrington, who speaks on public order for the National Police Chiefs' Council.
"There are 130 additional units across the country, which means that almost 4,000 additional officers with public order training will have to be deployed.
"So if you plan on causing trouble and disorder, our message is very simple: we are watching you."