London braced on Sunday for more violence after some of the worst riots in the British capital for years which politicians and police blamed on criminal thugs but residents attributed to local tensions and anger over hardship.

Rioters throwing petrol bombs rampaged overnight through the deprived district of Tottenham in north London, setting police patrol cars, buildings and a double-decker bus on fire.

"There is Twitter conversations that people are being asked to meet again down in Tottenham, so we are all concerned but clearly we will be much better prepared this evening," Richard Barnes, London's Deputy Mayor, told BBC TV.

Police Commander Adrian Hanstock told Reuters there was "a lot of ill-informed and inaccurate speculation on social media sites" that could inflame the situation.

"Should we receive any indication that there will be any further violence or offending, there is a robust policing plan in place and we will respond appropriately with the resources available to us," he said.

Police later said they were called to Enfield, a few miles north of Tottenham, where youths had smashed two shop windows and damaged a police car. "Not a riot, but serious disturbance," the local member of parliament (MP) Nick de Bois wrote on his Twitter site.

BOMBARDED WITH MISSILES, BOTTLES

Police said 26 officers were injured as rioters bombarded them overnight with missiles and bottles, looted buildings including banks, shops and council offices, and torched three patrol cars near Tottenham police station.

The riots erupted after a street protest over the fatal shooting of a man by armed police this week. Residents said they had to flee their homes as mounted police and riot officers on foot charged the crowd to push rioters back.

As day broke, the Metropolitan Police, which will handle next year's London Olympic Games in what is expected to be Britain's biggest peacetime police operation, faced questions about how the trouble had been allowed to escalate.

The disturbance was finally brought under control on Sunday after hours of sporadic clashes. Buildings were still shouldering, bricks littered the roads and burglar alarms continued to ring out.

At a nearby retail park, electrical stores and mobile phone shops had been ransacked, with boxes for large plasma TVs discarded outside, along with CDs and glass from smashed windows. "They have taken almost everything," said Saad Kamal, 27, branch manager of retailer JD Sports. "Whatever is left is damaged."

APPEAL FOR CALM

Local MP David Lammy said it was not known if everyone had escaped flats above shops that were gutted by fire. "A community that was already hurting has now had the heart ripped out of it," he told reporters.

Police and community leaders said local people had been horrified by what happened and appealed for calm.

The trouble broke out on Saturday night following the peaceful demonstration over the shooting of Mark Duggan, 29, who was killed after an exchange of gunfire with police on Thursday. Duggan's death is now being investigated by the independent police watchdog.

The riots come amid deepening gloom in Britain, with the economy struggling to grow while the government is imposing deep public spending cuts and tax rises brought into help eliminate a budget deficit which peaked at more than 10 percent of GDP.

"Tottenham is a deprived area. Unemployment is very, very high ... they are frustrated," said Uzodinma Wigwe, 49, who was made redundant from his job as a cleaner recently.

"We know we have been victimised by this government, we know we are being neglected by the government," said another middle-aged man who declined to give his name. "How can you make one million youths unemployed and expect us to sit down?"

Tottenham has a large number of ethnic minorities and includes areas with the highest unemployment rates in London. It also has a history of racial tension with local young people, especially blacks, resenting police behavior including the use of stop and search powers.

NOTORIOUS RACE RIOT IN 1985

The disorder was close to where one of Britain's most notorious race riots occurred in 1985, when police officer Keith Blakelock was hacked to death on the deprived Broadwater Farm housing estate during widespread disturbances.

Locals said there had been growing anger recently about police behavior. "I've lived in Broadwater Farm for 20 odd years and from day one, police always pre-judge Turks and black people," said a 23-year-old community worker of Turkish origin who would not give his name.

Fingers were also pointed at the police for failing to anticipate the trouble, although Commander Hanstock said there had been no hint of what was coming. He said they expected to add to the 55 people already arrested.

The London force has been heavily criticised for its handling of recent large protests against austerity measures, while its chief and the top counter-terrorism officer have quit over the handling of the News Corp phone-hacking scandal.

"I'm concerned that what was peaceful protest ... turned into this and it seemed to go on for many hours before we saw the kind of policing that I think is appropriate," Lammy said.

Politicians said criminals and thugs, rather than those with genuine grievances, had taken advantage of the situation.

"The rioting in Tottenham last night was utterly unacceptable," a spokesman for Prime Minister David Cameron said. "There is no justification for the aggression the police and the public faced, or for the damage to property."

The capital also saw riots at the end of last year when protests against government plans to raise tuition fees for university students in the center of London turned violent.

During the most serious disturbances last December, rioters targeted the limousine belonging to heir-to-the-throne Prince Charles and his wife Camilla.