Ten railway services were halted at and to Gare du Nord station, including Eurostar services from Paris to London and Brussels, as well as regional French trains. Thousands of passengers’ travel plans have been disrupted as a result.

Workers found the bomb near a railway track in the Saint-Denis area, north of Paris, at around 4am on Friday morning.

Eurostar said in a statement: “If your train has been cancelled, please change your journey for a different date of travel or claim a refund. We're very sorry for the disruption to your journey and the inconvenience caused.”

Discovery of World War-era bombs is not uncommon in France. However, they are not typically discovered in such densely populated areas, such as near the capital.

On the broadcaster Sud Radio, French Minister of Transport Philippe Tabarot assured people they should have “no fear” of explosion.

Roads throughout Paris have also closed as disposal teams work to remove the bomb.