A quarter of all Eurostar trains will be cancelled on Friday and over the weekend after arson attacks caused disruption ahead of the opening of the Olympics in France.
The rail operator, which runs international services from London St Pancras, said the cancellations were because of “co-ordinated” vandalism on other high-speed lines, with customers told to cancel their trips where possible.
The disruption coincides with people travelling to see the opening ceremony of the Paris 2024 Olympic Games, and come as millions embark on summer getaways.
French rail company SNCF said a series of incidents overnight had affected travel to and from London and Belgium, and across the north, east and west of France.
French transport minister Patrice Vergriete told broadcasters incendiary devices had been discovered and people had fled from the fires.
Three fires were reported near the tracks of the French Atlantique, Nord and Est high-speed lines.