Protesters hurled eggs at the country's finance ministry and scaled the sides of the Colosseum on Thursday as nationwide labor demonstrations heated up.

Students and union members were the driving force behind the demonstrations, rallying on Twitter under the hashtag #socialstrike.

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Several were injured in in Padua where protesters clashed with police. The violence erupted when members of the march headed toward the local offices of Premier Matteo Renzi's centre-left Democratic Party (PD).

Actions in Milan also took a violent turn. Students threw bottles, flares and other objects and police fired teargas and charged at the group as they tried to push through a police line.

In Rome, protesters scaled scaffolding on the side of the iconic Colosseum to hang union banners. Elsewhere in the capital city, protesters marched past the finance ministry and threw eggs and fireworks at the ministry of economy and finances.

Confederazione dei Comitati di Base (Cobas) one of the unions organizing the protests say they are protesting against Renzi's austerity policies, the EU and the proposed Jobs Act.

The proposed act, which would make it easier for companies to fire workers, is at the center of the protests, with unions and students opposing the labor reforms.

Union leaders have been stunned by Renzi's refusal to negotiate, a bold break with a decades-old government practice of courting both labor and industrial leaders before launching economic initiatives. This week, the union, angry that Renzi won't budge, called a second nationwide general strike for Dec. 5.

"If he thinks he is going to split the country and defeat the workers, he is probably going to get a nasty surprise," said Rosario Rappa, a protester from the FIOM metalworker's union.

The labor reform will "reduce precarious jobs and extend social assistance [and] give more opportunity to the 42% of young people who are jobless," said Alessandro Gozi, a government undersecretary.

The Associated Press contributed to this report