Italian police clashed Sunday with thousands of demonstrators protesting a high-speed rail line linking Italy to France.
Officials said anarchists infiltrated the protest and were responsible for injuring nearly 200 police officers. It was not immediately clear how serious the injuries were or how many protesters were injured. At least five people were arrested.
President Giorgio Napolitano condemned the violence and said police were right to react with "maximum" force to root out the anarchists from legitimate protesters, who included families and 23 mayors from the Val di Susa area in northwest Italy.
Riot police fired tear gas to try to contain the protesters, who hurled stones and firebombs as they marched toward a new construction site for the railway that opened this week in Chiomonte, west of Turin.
Construction of the high-speed rail on the Italian side was brought to a standstill by protests before and after the Turin Winter Olympics in 2006. This week, protests resumed after the Chiomonte site opened.
Many residents between Turin and the French border say a high-speed train line would ruin the area, and they object to the drilling of a tunnel which they claim could release potentially harmful materials in the atmosphere.