Demonstrators clashed with police on Saturday as tens of thousands marched through Rome to protest against the government's intensifying austerity programme.

They chanted slogans against unemployment and government cuts to benefits and social housing programmes.

A small contingent of anarchists set off smoke bombs and fireworks and threw eggs, while many camped throughout the night in front of the Infrastructure Ministry.

Prime Minister Enrico Letta's 2014 budget, which was unveiled on Tuesday, has become a focus of huge discontent, with trade unions campaigning against freezes on public-sector salaries and little sign of a hoped-for easing of the tax burden on workers.

Italian unemployment is running at an all-time high of 12.2 per cant, with the youth jobless rate at an incredible 40.1 per cent.

Organisers said at least 70,000 people had joined the march that started in Piazza San Giovanni and proceeded through the city.

The demonstrators held up banners against unemployment, lack of affordable housing and the planned TAV high-speed train link to France.

Opponents of the project say that the money to build the line should have instead been used to help the poor and the unemployed.

Matteo, a 20-year-old student from the eastern Marche region, said: "This protest is to demand basic rights - a job paying a wage and adequate housing.

"All the most downtrodden people are here to protest - unemployed people, students, immigrants and workers without job security."

At least 4,000 police had been called out to control the demonstration.

Saturday's protest followed hard on the heels of action on Friday by transport unions.

A 24-hour nationwide strike caused airports in Rome, Naples, Milan and Bologna to cancel some flights.

Some school and health workers also went on strike.

The USB and Cobas unions organised the strike to protest against austerity measures reducing transport budgets.

USB co-ordinator Pierpaolo Leonardi accused the government of imposing EU directives without concern for the impact on workers.

A 600-strong protest was also staged by transport workers in Milan.