'Pitchfork' protests enter 4th day
Teargas, scuffles at French border12 December, 11:48
Rome Mayor Ignazio Marino said he was "worried" that a large Forconi demonstration slated to take place in the Italian capital next week could turn violent.
"It is very easy for violent people to infiltrate (an otherwise peaceful protest)," Marino told journalists during a visit to New York.
Pitchfork leaders had vowed a large-scale demonstration in Rome if MPs did not abstain from a confidence vote in parliament on Wednesday.
The government led by Premier Enrico Letta passed the vote in both houses of parliament.
Interior Minister Angelino Alfano was set to brief the Lower House on the state of public order, while the government has promised to take a hard line with the demonstrations.
Demonstrations have spanned south to north since they began on Monday, with cities such as Milan, Turin and Genoa showing the greatest turnout.
Protesters opposed to austerity-driven tax hikes, but also taking up other anti-government causes, have occupied roads, squares and railways, snarling traffic, blocking trains and disrupting pre-Christmas commerce.