The worst riots in Britain for decades spread to new cities on a fourth night as youths ran amok in Manchester and the industrial Midlands, after 16,000 police took to the streets of London.
In Manchester, Britain's third-largest city, youths smashed shop windows and looted shops and chased photographers away from the scene, in what police described as the worst violence in 30 years.
Elsewhere, hooded rioters set fire to buildings in West Bromwich and Wolverhampton in central England and a police station in nearby Nottingham was firebombed, although there were no reported injuries.
Looters also targeted shops in the second city of Birmingham for another night and police were pelted with missiles in the north west city of Liverpool.
But in London there was no repeat of the wave of violence which left parts of the capital in flames on Monday night, as vigilante mobs took to the streets to defend their communities.
Police were bracing for more trouble after what they said was the worst night of disorder in living memory in the British capital, and their numbers were ramped up from 6,000 to 16,000 on Tuesday night as Prime Minister David Cameron vowed to do "everything necessary to restore order to the streets".
Shops in many parts of London closed early and put down their shutters on the advice of the police.
The focus of Tuesday's violence was Manchester in northwest England, where police were driven back by gangs of hundreds of youths who covered their faces with scarves and ski masks.
Gangs smashed their way into shoe shops and electronics stores and set fire to a girls' clothing store in the city centre.
Two raiders smashed the glass entrance of the Arndale shopping centre, Manchester's main shopping mall, allowing hundreds of youths to pour into a shop and emerge with armfuls of clothes and shoes.
Assistant chief constable Garry Shewan of Greater Manchester Police, who joined the force after moving to the city in 1981, called the scenes "senseless violence and senseless criminality on a scale I have never witnessed before."
Glen Barkworth, general manager of the Arndale centre, told BBC TV he had seen two shops "both breached, looted and then torched. I've witnessed youths picking up gratings, throwing them through the doors of Footasylum (a shop) where 50 youths cascaded into the unit, looting.
There were similar scenes in Birmingham, and in the neighbouring town of Wolverhampton youths clashed with riot police brandishing shields.
In London, hundreds of Sikhs took to the streets to defend the community of Southall in the west while similar mobs of football supporters congregated in Eltham, south London, in an effort to deter looters.
A witness also filmed a gang of men running down a street in Enfield, at the centre of much of the previous trouble, shouting "England, England, England".
In a development which will do nothing to calm tensions, Britain's police watchdog said it found no evidence that Mark Duggan -- whose shooting by police last week was the catalyst for the riots in London -- had fired a gun at officers.
In a pre-planned operation, armed officers stopped the taxi in which Duggan, 29, was travelling in the multi-ethnic district of Tottenham in north London. Shots were fired and Duggan died at the scene.
Duggan's family said they were "completely gutted" by the findings and called for "answers" from the police.
Despite the controversy surrounding the shooting, Cameron warned rioters: "You will feel the full force of the law."
Police have arrested 685 people in London in three days, while 111 police officers were injured, Scotland Yard said.
Scotland Yard deputy assistant commissioner Stephen Kavanagh said the rampage by hundreds of hooded youths was "unprecedented" and police resources were stretched "to an extent I have never seen before".
He said plastic bullets -- used during sectarian unrest in Northern Ireland but never before in mainland Britain -- have been considered to stem the tide of unrest.
The violence has raised questions about security ahead of the 2012 London Olympic Games, and it prompted the cancellation of Wednesday's friendly between England and the Netherlands at Wembley Stadium.
The capital's mLondonayor Boris Johnson toured the area Tuesday after he returned hastily from holiday and was confronted by angry residents saying: "Why are you here now? It's too late."
The speaker of the House of Commons has agreed to recall parliament on Thursday so lawmakers could debate their response to the riots, Cameron said -- a highly unusual move highlighting the seriousness of the crisis.
A 26-year-old man found with a gunshot wound to the head in a car in Croydon died in hospital on Tuesday, police said, becoming the first fatality of the riots.