Saboteurs damaged rail infrastructure near the northern Italian city of Bologna on Saturday morning, disrupting train travel on the first full day of the Winter Olympics, the transport ministry said.

Police reported three separate incidents at different locations, causing delays of more than two hours in some cases for express, intercity and regional services.

The ministry called it an act of “serious sabotage”, adding that it echoed the opening day of the 2024 Summer Olympics in Paris, when saboteurs attacked France’s high-speed TGV train network, causing travel chaos.

“These unprecedentedly serious actions in no way tarnish Italy’s image in the world, an image that will make the Games even more convincing and positive,” said the ministry headed by Deputy Prime Minister Matteo Salvini.

State railway Ferrovie dello Stato (FS) had to temporarily close its high-speed station in Bologna, but traffic was slowly returning to normal by Saturday afternoon, it said.

Police said the cabin containing the switch was set on fire before dawn near the Adriatic city of Pesaro. Hours later, electrical cables used to detect the speed of trains were found cut in Bologna, while a rudimentary explosive device was discovered next to the tracks at a nearby location.

A spokeswoman said no one had claimed responsibility for the incidents, which appeared to be coordinated.

Bologna is a major hub for Italy’s east-west rail lines, and is also a key hub connecting the south with northern cities such as Milan and Venice.

Milan is one of the hosts of the Winter Games along with Cortina, which can be reached by train from Venice.