ROME (Reuters) - Hundreds of hooded, masked protesters rampaged through Rome in some of the worst violence in the Italian capital for years Saturday, torching cars and breaking windows during a larger peaceful protest against elites blamed for economic downturn.
Police repeatedly fired tear gas and water cannon in attempts to disperse them but the clashes with a minority of violent demonstrators stretched into the evening, hours after tens of thousands of people in Rome joined a global "day of rage" against bankers and politicians.
Smoke rose over many parts of the neighborhood between the Colosseum and St John's Basilica, forcing many residents and peaceful demonstrators to run into buildings and churches for shelter as militant protesters ran wild.
After police managed to push the well-organized radicals away from the St John's area, they ravaged a major thoroughfare, the Via Merulana -- building barricades with garbage cans and setting the netting of the scaffolding of a building on fire.
Discontent is smouldering in Italy over high unemployment, political paralysis and 60 billion euros ($83 billion) of austerity measures that have raised taxes and the cost of health care.
The violence at times resembled urban guerrilla warfare as protesters hurled rocks, bottles and fireworks at police, who responded by repeatedly charging the demonstrators.
Tens of people were injured, one of them critically, among the police and demonstrators, officials said.
At one point radicals surrounded a police van near St John's Basilica, pelted it with rock and bottles, and set it on fire. The two occupants managed to escape, television footage showed.
Some peaceful demonstrators also clashed with the militants and turned some of them over to police.
BERLUSCONI DEMANDS CRACKDOWN ON RIOTERS
Prime Minister Silvio Berlusconi said those responsible for the rash of violence must be identified and punished, calling the rioting "a very worrying sign for civil society ... They (radicals) must be condemned by everyone without reservation."
Rome Mayor Gianni Alemanno ordered all public museums in the capital closed for security reasons and he and politicians across Italy's political spectrum denounced the disturbances.
"Unacceptable violence and devastation is happening right now on the streets of Rome," said Pierluigi Bersani, head of the Democratic Party, the largest in the opposition.
"Those who are carrying out what is nothing less than urban guerrilla warfare are hurting the cause of people around the world who are trying to freely express their discontent with the world economic situation," he said.
Alemanno, noting that the demonstrators had called themselves "the indignant ones," said: "Those who are really indignant are the citizens of Rome."
The protest was one of many staged around the world on Saturday to show solidarity with the Occupy Wall Street movement in the United States, venting anger over years of economic and financial crisis since a global credit boom went bust in 2007.
The demonstration began peacefully but turned violent when hundreds of hooded radicals known as "black blocs," who had infiltrated the larger group, set cars and garbage bins on fire.
The radicals, some of whom Alemanno said probably came from elsewhere in Europe to help their Italian comrades, then charged through several streets around the Colosseum, trashing windows of stores and banks.
One building believed to be a Defense Ministry annex caught fire after the flames spread from a car. The protesters had earlier forced their way into the annex and trashed its offices.
"The violence ruined the day but I expected it to end this way," said Matteo Martini, 29. "People are tired and angry and can't take it anymore. You can start a march peacefully but unless you break or hurl something no one hears you."
Italy's fractious coalition government has been forced to push through austerity measures to try to stop the economy -- the euro zone's third largest and one of its heaviest debtors -- from being sucked into the bloc's debt crisis.
Hours after the demonstration began police were still firing tear gas canisters and training water cannon on rioters in Piazza San Giovanni, the terminus of the demonstration, where a final rally was due to be held.
Masked demonstrators assaulted police vans with rocks, bottles and clubs in the San Giovanni area, which filled up with tear gas as police helicopters hovered above.
Some of the peaceful demonstrators tried to take refuge on the steps of St. John's Basilica, one of Rome's largest churches and used by Pope Benedict in his capacity as bishop of Rome.
The streets of central Rome were littered with rocks, bottles and garbage bins that had been overturned, and fire brigades drove around the city trying to put out the fires.
(Editing by Mark Heinrich)