High-speed rail lines in France have been hit by several “malicious acts” which have heavily disrupted services on the day of the Olympics opening ceremony, according to the national rail company. Travel to and from London beneath the English Channel, to neighbouring Belgium and across the west, north and east of France were affected by what SNCF called a series of co-ordinated incidents overnight.

Government officials denounced the incidents happening around France hours before the opening ceremony of Paris 2024, though there was no immediate sign of a link to the Games. National police said authorities are investigating what happened. French media reported a large fire on a busy western route.

Transport minister Patrice Vergriete said in a post on X that he “firmly condemns these criminal incidents” and that SNCF is working to restore services. Sports minister Amelie Oudea-Castera said authorities are working to “evaluate the impact on travellers, athletes, and ensure the transport of all delegations to the competition sites” for the Olympics.

Speaking on BFM television, she said: “Playing against the Games is playing against France, against your own camp, against your country.”

Paris police chief Laurent Nunez, speaking on France Info radio, said he would send reinforcement to overcrowded stations in relation to the SNCF incidents.

Passengers at St Pancras in London were warned to expect delays of around an hour to their Eurostar journeys. Announcements in the departure hall at the international terminus informed travellers heading to Paris that there was a problem with overhead power supplies. It was then confirmed by Eurostar shortly after that several trains had been cancelled and others delayed.