Riots flared overnight in some English cities and towns but London was mostly calm as thousands of police deployed on its streets following three nights of rioting and looting in the British capital.
David Cameron, the British prime minister, on Wednesday vowed to arrest, prosecute and imprison those responsible for the disorder, speaking in Downing Street after hosting the second meeting of the government's crisis committee, COBRA, in 24 hours.
"We will not allow a culture of fear to exist on the streets," Cameron said, adding that more "robust policing" had been effective overnight in London.
Police had been authorised to use baton rounds, while contingency plans had been made for the use of water cannons in tackling further riots, he said.
"We will do whatever is necessary to restore law and order onto our streets," Cameron said. "Nothing is off the table."
Police have made 1,069 arrests across the country in response to the trouble, including 768 in London, 109 in the West Midlands and 90 in Nottingham. At least 167 people have been charged so far.
London was quieter on Tuesday night but the unrest spread to other cities including Manchester in the northwest and Birmingham, where three men died early on Wednesday after being hit by a car during riots, officials said.
Police said they had arrested a man and launched a murder inquiry after the incident which happened at 00:00 GMT as Britain's second biggest city suffered from another night of riots.
Paramedics said they found around 80 people at the scene after the men were hit by the car. Two of the men were pronounced dead at the scene and the third died later in hospital.
The BBC reported that the men who died had just come out of a mosque and were protecting their neighbourhood during the riots.
Around 200 people from Birmingham's Asian community gathered outside the hospital where the victims were taken. Riot police were also stationed there, the BBC said.
In Salford, part of greater Manchester in northwest England, rioters threw bricks at police and set fire to buildings on Tuesday night.
Television pictures showed flames leaping from shops and cars in Salford and Manchester, and plumes of thick black smoke billowing across roads. In central Manchester, police said a clothes shop was set alight.
Further south in West Bromwich and Wolverhampton, cars were burned and stores raided.
A gang of up to 40 men firebombed a police station in the central English city of Nottingham but no injuries were reported, police said. At least 90 arrests were made and 10 police cars damaged in the city.
In Liverpool, a Reuters reporter saw police with riot shields pushing back youths hurling bricks. Police said four fire engines were attacked.
In the western city of Gloucester, police and firefighters tackled a blaze and disturbance in the city's Brunswick district.
London was mostly quiet after a huge boost in police numbers on Tuesday evening which saw 16,000 officers on the streets, compared to the 6,000 out on Monday night.
Commuters hurried home early, shops shut and many shopkeepers boarded their windows as the city prepared nervously for more of the violence that had erupted in its neighbourhoods.
Police arrested 81 people overnight, across London, for various offences, filling the city's cells to capacity four nights since the trouble started.
Also, many Londoners took to the streets in their hundreds to defend their communities.
Hundreds of Sikhs, many dressed in traditional outfits, gathered outside their gurdwara, or temple, in Southall, west London, after earlier rumours circulated it was next on the looters' hitlist.
Around 200 locals in Enfield, the north London borough at the heart of previous attacks, strode through the area to "protect their streets", an AFP correspondent said.
The group became involved in a "minor skirmish" with a group of youths which it accused of taking part in criminal activity, the Guardian newspaper reported.
Amateur video footage released on Wednesday showed a group of around 100 men running down an Enfield street chanting "England, England, England".
A similar number of people congregated in the south-east suburb of Eltham. "This is a white working class area and we are here to protect our community," one man told the Guardian.
In the north London districts of Hackney and Kentish Town, mainly Turkish shopkeepers sat outside their shops into the early hours, many with makeshift weapons by their side.
Other Londoners tried to clear up the mess.
Hundreds of volunteers gathered on Tuesday morning in Clapham, south of the River Thames, to help clean up.
Cameron told reporters on Tuesday: "This is criminality pure and simple and it has to be confronted and defeated. People should be in no doubt that we will do everything necessary to restore order to Britain's streets."
The unrest poses a new challenge to Cameron as Britain's economy struggles to grow while his government slashes public spending and raises taxes to cut a yawning budget deficit - moves that some commentators say have aggravated the plight of young people in inner cities.
It also shows the world an ugly side of London less than a year before it hosts the 2012 Olympic Games, an event that officials hope will serve as a showcase for the city in the way that April's royal wedding did.
The London 2012 Organising Committee hosted an International Olympic Committee visit "as planned" on Tuesday and said the violence would not hurt preparations for the Olympics.
The first riots broke out on Saturday in north London's Tottenham neighbourhood, when a peaceful protest over the fatal shooting by police of a 29-year-old man, Mark Duggan, two days earlier led to violence.
While the police have been accused of failing to bring the situation under control by going in softly to spare local sensibilities, they are likely to come under renewed pressure over the Duggan incident after a watchdog said on Tuesday there was no evidence that a handgun retrieved at the scene had been fired.