At least 40 people have been injured in demonstrations against a planned high-speed rail line between France and Italy. Some of those hurt are reported to be among the some 2,000-strong security force deployed on the Italian end of the project — others are protesters.

The clashes occurred as workers prepared to start tunnel boring in the Susa Valley near Turin. It means chewing through 53 kilometres of mountain.

The authorities’ plan is to slash travel time between Milan and Paris from seven hours to four, and form a strategic link in the European network.

The next phase of tunnel construction has to start before the end of this month if the 15 billion euro project is to benefit from a tranche of European subsidies.

Valley residents oppose the cross-border development on grounds it will damage the environment.