The Tottenham riots spread across London Monday, with violence erupting in many of the British capital's outer neighborhoods.

What started as a peaceful protest in the North London neighborhood of Tottenham has become a citywide disaster, lasting three days thus far. Rioting has been reported in several districts, including Hackney in east London and Peckham and Lewisham in south London.

Demonstrators and hooded youths -- which are typical in London protests -- threw firebombs at police officers and torched property. In Tottenham, store windows were smashed and whole buildings burned to the ground.

The neighborhoods most affected by the turmoil are traditionally low-income, multi-ethnic areas. The riots were spurred when police shot and killed Mark Duggan in Tottenham. Mounted officers and riot police responded to the unrest by charging protesters, possibly escalating the violence.

Authorities promised Sunday that further demonstrations will be met with the full power of the Metropolitan police force.

"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," Police Commander Adrian Hanstock told Reuters.

Yet, despite the warning, rioters in Peckhman in South London on Monday afternoon set fire to a building and a number of cars. Additionally, there has been widespread looting, with electrical stores and mobile phone shops targeted.

A total of 215 people have been arrested so far and 27 charged. Police reported at least 26 officers injured.

"The violence we've seen, the looting we've seen, the thuggery we've seen, this is sheer criminality ... These people will be brought to justice. They will be made to face the consequences of their actions," said Home Secretary Theresa May.

But the violence is likely about more than just the death of Duggan, and the outflow of violence is also an outflow of frustration. London, like many European countries, is in the midst of serious fiscal inadequacies, and poor neighborhoods such as Tottenham and Hackney suffer most. Unemployment is rampant in such areas, especially in North London.

"Tottenham is a deprived area. Unemployment is very, very high ... they are frustrated," recently laid-off Uzodinma Wigwe told Reuters.

"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?"

Metro police, as well as a private agency, are investigating the riots and the shooting.

Sometimes, people use demonstrations as an excuse for violence, regardless of cause. Recent peaceful rallies in London against government austerity measures were marred by a few rabble-rousers.

A protest in London in March erupted in a fight between self-proclaimed anarchists and the police. During a nearly 500,000-person march from Piccadilly Circus to Hyde Park to Parliament, isolated clashes between with the police lead to 214 arrests and 31 injured police officers, one of whom needed immediate medical attention.

Police fired tear gas on the anarchists, who in turn threw rocks, bottles, paint and light bulbs filled with ammonia at the officers.

On Piccadilly, across the street from the Ritz hotel, people wearing scarves and t-shirts over their faces broke the windows of an HSBC bank and a Starbucks, while spray-painting everything they could find, including telephone booths, mail boxes, storefronts and even the street itself. The instigators also stormed and occupied the luxury department store Fortnum & Mason and a number of clothing stores on Oxford Street.

Earlier in the year, student protests against a tuition hike also turned a vicious corner, where again students and police clashed on London streets. Windows were broken, and Prince Charles' Rolls Royce was assaulted while he drove down Regent Street.