David Cameron vows to restore order

Thousands of police prepared to deploy on London's streets last night to head off the rioters and looters who have rampaged through parts of the British capital for the past three nights.

Community leaders tried to explain the violence, London's worst in decades, as rooted in growing disparities in wealth and opportunity in the multi-ethnic city.

Gangs ransacking shops, stealing clothes, shoes and electronic goods, torching cars and fighting police, stunned Londoners.

"This is criminality pure and simple, and it has to be confronted and defeated," British Prime Minister David Cameron said after he cut short a family holiday in Tuscany to return home to deal with the crisis.

"People should be in no doubt that we will do everything necessary to restore order to Britain's streets," he said.

Cameron took the rare step of recalling parliament from recess.

The unrest comes as Britain's economy struggles to grow as the government slashes public spending and raises taxes to help eliminate a budget deficit. Commentators say these moves aggravated the plight of inner-city youth.

It also shows an ugly side of London to the world less than a year before it hosts the Olympic Games, which city officials hope will showcase the city.

"Last night was the worst the [Metropolitan Police] have seen in current memory for unacceptable levels of widespread looting, fires and disorder," the police said.

Police had arrested more than 200 people overnight and 450 over the three nights. Cells are now full of detainees. The police said 44 police officers and 14 members of the public were injured.

Cameron said that 16000 police would be on the streets last night. On Monday night there were 6000.

Londoners feared another night of trouble with youth gangs reportedly coordinating their movements though social networks - particularly secure-access BlackBerry Messenger groups - and targeting shops.

From riot-scarred Hackney to upmarket Sloane Square shops were closing early or putting up boards. Shops and pubs closed early in Wimbledon yesterday afternoon as rumours circulated that gangs would target the upscale neighbourhood, witnesses said.

Tottenham MP David Lammy said he was asking BlackBerry to suspend its messaging service.

It was "clear this is one of [the] reasons why unsophisticated criminals are outfoxing an otherwise sophisticated police force", he said.

The BBC said a man was shot dead in Croydon, south London, the first fatality of riots that spread to Britain's second-largest city Birmingham and other centres.

The police have been criticised for not taking control.