Tens of thousands of people marched through Rome in a "No Monti Day", some throwing eggs and spraying graffiti to protest against austerity measures introduced by Prime Minister Mario Monti's government.

Appointed in November when Italy risked being sucked into the euro zone debt crisis, Monti has pushed through painful austerity measures to cut the country's massive debt, including tax hikes, spending cuts and a pension overhaul.

"We are here against Monti and his politics, the same politics as all over Europe, that brought Greece to its knees and that are destroying half of Europe, public schools, health care," said demonstrator Giorgio Cremaschi.

Police were on alert for possible infiltration by extremists who turned past demonstrations violent. But while protesters threw eggs at bank windows and set off firecrackers, no major incidents were reported.

"United with a Europe that is rebelling. Let's get rid of the Monti government," read one of the banners held at the demonstration.

Unemployment in Italy has risen to its highest since monthly records began in 2004 and unions are locked in growing disputes with companies over plant closures and layoffs.

"It's been years that there have been no investments, instead it's all outsourced and privatised, we are here to say enough and we hope this voice will grow," said another demonstrator, Caterina Fida.

Monti has defended the austerity measures, saying he believes his technocrat government will be remembered for having helped Italy pull itself out of a deep economic crisis without needing to resort to external aid.

In another demonstration in northern Italy, a small group of protesters scuffled with police near where Monti was addressing a rally on the theme of family values.