Police officers in riot gear block a road near a burning car on a street in Hackney, east London August 8, 2011. Youths hurled missiles at police in northeast London on Monday as violence broke out in the British capital for a third night.[Photo/Agencies]

LONDON - Violence and looting flared across London on Tuesday - and spread to a second major city - as shops and cars were set ablaze and authorities struggled to contain a third night of unrest in Britain's capital, which will host next summer's Olympic Games.

The worst rioting in London in decades saw buildings, vehicles and garbage dumps set alight, stores burglarized and police officers pelted with bottles and fireworks, as groups of young people rampaged through neighborhoods across the capital from mid-afternoon Monday into the early hours of Tuesday.

A massive blaze swept through a 100-year-old family-run furniture store in the town of Croydon, in south London, and sent thick plumes of smoke into the air, forcing nearby homes to be evacuated.

Police confirmed they were investigating a nonfatal shooting in Croydon, but were unable to say whether or not the incident was linked to the chaos.

In the nation's central city of Birmingham, dozens of people attacked shops in a main retail district - spreading the chaos beyond London for the first time since violence broke out on Saturday night.

As authorities struggled to keep pace with unrest at dozens of flashpoints, Prime Minister David Cameron announced he would cut short his summer vacation in Italy and will convene a meeting of the government's crisis committee on Tuesday to toughen the response to the violence.

In the Hackney area of east London, hundreds of youths attacked shops and set fire to cars, leaving a trail of burning trash and shattered glass. Looters ducked into a small convenience store as the blackened husks of two cars burned low nearby, filling plastic shopping bags with alcohol, cigarettes, candy and toilet paper.

"This is the uprising of the working class, we're redistributing the wealth," said Bryn Phillips, a 28-year-old self-described anarchist, as young people emerged from the store with chocolate bars and ice cream cones.

Phillips claimed rioters were motivated by distrust of the police, and drew a link between the rage on London's street and insurgent right-wing politics in the United States. "In America you have the tea party, in England you've got this," he said.

Police acknowledged Tuesday that major new bouts of violence had flared in at least five locations, badly stretching their resources. Many more neighborhoods saw mobs vandalize commercial streets or break into buildings - some acting with virtual impunity, as authorities struggled to deploy officers to the every scene of unrest.

"The violence we have seen is simply inexcusable. Ordinary people have had their lives turned upside down by this mindless thuggery," police commander Christine Jones said, as she confirmed that 225 people had been arrested and 36 people charged with offenses so far.

Violence broke out late Saturday in London's northern Tottenham district when peaceful protest over the fatal police shooting of Mark Duggan, a 29-year-old father of four who was gunned down in disputed circumstances Thursday, turned violent. Two police cars and a double-decker bus were set alight, stores were looted and several buildings along Tottenham's main street - five miles (eight kilometers) from the site of the 2012 Olympics - were reduced to smoldering shells.

Though the unrest escalated through Sunday as disorder spread among neighboring areas, the crisis worsened Monday - as violence touched areas in the east and south of London previously untroubled by the chaos, leaving young thugs free to set fires and steal from high street stores.

"There is significant disorder breaking out in a number of our communities across London," Tim Godwin, the acting London police commissioner said Monday, acknowledging that 1,700 extra officers had been deployed across London, but were struggling to halt the unrest.

Some residents called for police to deploy water cannons to disperse rioters, or call on the military for support.

About a hundred young people clashed early Tuesday with police in the Camden and Chalk Farm areas of north London, while others tore through a department store in the busy south London suburb of Clapham.

The small groups of youths - most with their heads and faces covered - used SMS messages, instant messaging on BlackBerry cell phones and social media such as Twitter to coordinate their attacks and outwit the police.

Once the preserve of businesspeople, BlackBerry handsets are popular with teenagers, thanks to their free, fast instant messaging system. Blackberry's manufacturer, Research in Motion, said in a statement that they were assisting authorities in their investigation and "feel for those impacted by the riots in London".

Police were also monitoring Twitter, and warned that those who posted messages inciting the violence could face arrest.