Thousands of people took to the streets of Rome on Saturday for an anti-austerity protest, with a massive security presence amid fears of clashes.
"We are laying siege to the city!" some students chanted as they marched through central Rome.
Police have seized potential weapons including chains, helmets, clubs and a knife and have detained 14 people ahead of the protest.
Between 3,000 and 4,000 police officers have been deployed, Italian media reports said, and protest organisers say they expect more than 20,000 to join.
The demonstration brings together a variety of groups including migrant rights advocates, campaigners for affordable housing and protesters against a new high-speed rail link in the Alps.
Some of the protesters had camped out overnight on Piazza San Giovanni square following a trade union demonstration and transport strike on Friday.
Many shops in the area of the Italian capital remained shuttered for the protest in a bid to minimise damage to property.
Reports suggest demonstrators may be planning to occupy buildings, including hotels, in protest over a lack of accommodation for poor families who have been hit hard by the recession, the longest Italy has suffered since the post-war period.