More than 180 Italian police and protesters were injured on Sunday during demonstrations against a high-speed railway tunnel linking Italy to France, Reuters reports.

About 6,000 people joined initially peaceful marches in the Val di Susa area, near Turin, police said, protesting against a tunnel they say will damage the environment and spoil the picturesque Alpine valley.

But scuffles broke out at several points along the boundaries of the construction site. Protesters threw stones and firecrackers and police responded with tear gas.

At least 188 police officers were injured in the clashes, while several protesters and a site worker were also hurt.

Police arrested at least five people and attempted to disperse hundreds of protesters near the enclosure, although some managed to breach the site fences.