Police said a track switch was set alight near Pesaro, on the Adriatic coast. Several hours later, police discovered severed electric cables near Bologna, along with a rudimentary explosive device left by a track nearby.

Bologna's rail station is a major transport hub, linking cities in the north and south, and east to west lines.

"These actions of unprecedented seriousness do not in any way tarnish Italy's image in the world, an image that the Games will make even more compelling and positive," said Deputy Prime Minister and Transport Minister Matteo Salvini.

A police spokesperson earlier said that they were investigating the incidents and that no one had claimed responsibility.