LONDON -- Eurostar trains to London, including all trains heading to northern France, stopped abruptly on Friday morning after an unexploded bomb dating back to World War II was discovered near the tracks, officials said.

The unexploded ordinance was discovered approximately 1.5 miles north of Gare du Nord in Saint Denis, an area just north of Paris where the Stade de France – the national stadium of France – is located and where dozens of Olympic events were held, including the closing ceremonies, last year.

“Traffic is interrupted between Paris Gare du Nord and La Plaine Stade France in both directions until 10:00 a.m. and disrupted on the rest of the line,” France's national train operator SNCF said in a statement on Friday morning. “If possible, we invite you to postpone your trip.”

The reason listed was due to “intervention by law enforcement” following the discovery of an unexploded bomb from the second World War near the tracks at Paris Nord, SNCF said.

Gare Du Nord in Paris is the busiest railway station in Europe by passenger numbers and served over 211 million people alone in 2022.

Dozens of passengers could be seen waiting in the station with their luggage as they watched trains being canceled across the passenger information boards.

It is unclear how large the ordinance is or how long it will take authorities to clear the area before regular services resumes.

The investigation is currently ongoing.

ABC News' Joe Simonetti, Morgan Winsor and Tom Soufi-Burridge contributed to this report.