Prime Minister Mario Monti on Friday said Italy was determined to build a high-speed rail line to France and warned of a firm response to protests after clashes that injured 13 police officers.
Monti "confirmed the intention of the government to follow up the implementation of this project", a government statement said, of the proposed high-speed rail link between Turin and Lyon.
"We will not tolerate any form of illegality and (the government) will oppose all forms of violence," it added.
Thirteen police officers were injured in clashes with protesters on February 29 in the northern Italian town of Chianocco.
Protesters threw rocks and police fired tear gas after security forces moved in to clear a section of motorway blocked for three days by protests against the building of the rail line through a picturesque section of the Alps.
The rail line will cost 20 billion euros ($26.4 billion) and is strongly opposed by some local residents in the Val di Susa in the Alps -- who say it is costly and bad for the environment.
Its supporters say it is a vital project for Europe and would shorten the journey between Paris and Milan to four hours instead of seven hours at the moment, as well as taking a lot of truck traffic off the motorways.
The project is expected to be completed by 2023.
The Italian government said Friday the project had "important advantages" for "infrastructure, environment and employment plans".