On its website, the FCDO has updated its “information about travel disruption to Eurostar and some French train services.”

The Foreign Office has issued an urgent warning for UK tourists travelling to France in the European Union. On its website, the FCDO has updated its “information about travel disruption to Eurostar and some French train services.”

Eurostar and some French train services are disrupted, following the discovery of an object on the tracks near Paris Gare du Nord. Foreign Office chiefs warned: “This includes all Eurostar services between Paris and London in both directions, and some RER, regional and TGV services.

“Check your operator’s advice before travelling.” The unexploded bomb weighing 500kg was found in the middle of a set of tracks during overnight maintenance work in the suburb of Saint Denis, about 1.5 miles (2.5km) from the Gare du Nord.

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All rail traffic to Gare du Nord, France’s busiest railway terminal, was closed as Paris police worked to disable the device. The French transport minister, Philippe Tabarot, told French radio before heading to the scene that teams were “massively mobilised” to deal with the device. He said: “There’s nothing to be afraid of, but there are procedures we have to respect.”

French railway operator SNCF told the French newspaper Libération that the unexploded WW2 bomb is estimated to weigh about 500 kg, of which 200 kg are explosives, and is one meter long. It was found 2 metres deep into the ground, in an area known for previous remains from the second world war.

A security perimeter of 500-meters remains in place. Traffic is not expected to resume before 4pm local time, Libération reported quoting a report from the French transport minister, Philippe Tabarot.

All Eurostar trains to and from Paris today have been cancelled, as reported earlier. The cancellations includes all services on lines: London-Paris, Paris-London, Brussels-Paris and Paris-Brussels.

“Customers can exchange their ticket for free to travel at a different time or date in the same travel class. This is subject to availability,” it added.