Anti-Olympic protesters marched peacefully through Milan on Saturday afternoon, holding signs, marching arm-in-arm, singing and dancing. But when night fell, the demonstration turned violent as some protesters targeted police and their vans, and officials responded with tear gas and water cannon. This comes as authorities separately investigate a series of incidents on rail lines in northern Italy that officials fear could be coordinated sabotage.

The protest march against Olympics organizers drew groups from the city, Lombardy and the rest of northern Italy. Demonstrators voiced opposition to the environmental impacts of constructing Olympic venues, as well as what they describe as the “economic and social harm” caused by the Games.

The march was organized by an activist organization called the Unsustainable Olympics Committee, which mobilized a wide coalition of grassroots sports groups, civic and environmental movements, students, housing activists, combative unions, pro‑Palestine networks and transfeminist collectives.

They have also spoken out more broadly against the Italian government’s “authoritarian security drift” and treatment of racial minorities.

The Winter Olympics 2026 had officially begun yesterday, with a star-studded opening ceremony at the famed San Siro stadium in Milan that celebrated Italy’s rich art and culture and featured Italian tenor Andrea Bocelli and American singer Mariah Carey.

After marching from Piazza Medaglie d’Oro, the protesters passed near the Olympic Village, which was secured by a large police cordon. Some demonstrators threw firecrackers and smoke bombs toward the athletes’ housing. The buildings were far enough away that none of the objects could actually reach them.

The march then diverted left onto Via Benaco, moving away from the Village with clashes beginning when the protest reached Piazzale Corvetto. A smaller group of protesters threw fireworks at police, who responded with a charge. Demonstrators later targeted police vans with additional fireworks. Officers deployed water cannons and tear gas in response.

Not all the protesters joined in on the clashes with authorities, with many demonstrators remaining in the main area of the square.

In the northern Italian city of Bologna, railway networks suffered severe disruptions Saturday, with fears of a “premeditated attack” on the Bologna railway lines, according to the country’s transport minister.

Three separate incidents of damage were uncovered, including the discovery of a rudimentary explosive device on a switch of the Bologna-Padova line, according to Italy’s rail network Ferrovie dello Stato and Ansa news agency.

Electrical cables on a high-speed line were also severed, and a fire was started at an electrical cabin in the Adriatic town of Pesaro, the railway network said.

Investigators are not ruling out sabotage carried out by anarchists, citing similarities to the sabotage that targeted the French network during the 2024 Paris Olympics, when France’s high-speed train lines were targeted by multiple malicious acts including arson.

Speaking from Bormio where he was attending the men’s downhill ski race, Infrastructure and Transport Minister Matteo Salvini strongly condemned the events as an “act of delinquency.”

“If it is confirmed that the interruption on the high-speed line is the result of a premeditated attack, on the first day of the Olympics, let’s say that someone wishes ill upon Italy,” Salvini said.

CNN’s Antonia Mortensen reported from Milan, Juan Pablo O’Connell from Rome and Aditi Sangal from New York. (CNN)