Italian security officials have confirmed police carried out raids and checks against suspected far-left and anarchist groups early Monday, in response to clashes with police in Rome over the weekend that left some 135 people injured.

What began on Saturday as part of a worldwide demonstration against corporate greed and income inequality inspired by the month-long Occupy Wall Street movement in New York devolved into urban warfare between protesters and police.

Cobblestones and chunks of sidewalk were hurled at police, shop windows and ATMs were smashed and cars were torched, with the city's mayor estimating that damage amounted to at least 1 million euros ($1.4 million).

'Unprecedented violence'

Officials said the raids targeted those believed to be behind the violence

Interior Minister Roberto Maroni has condemned the "unprecedented violence," saying "the violent protesters were using the march as a shield."

"I want the authors of this violence, who are real dyed-in-the-wool criminals, to pay as an example to others," he said.

Investigators said they were examining computer files and video footage, and were looking for possible weapon stockpiles.

Promoters of the main demonstration accused the police of failing to intervene to isolate the violent minority among the estimated 200,000 people who turned out for the Rome protest.

Author: Holly Fox (AFP, AP, dpa)

Editor: Martin Kuebler