An unexploded WWII bomb discovered near tracks leading to France's busiest train station has severely disrupted rail service as police work to disable the device.

The police successfully defused the explosive device, which weighs more than 1,000 pounds and was found near tracks north of the French capital during landscaping work.

Eurostar trains in a Paris train station have been cancelled following the discovery of an unexploded World War II bomb. The bomb was found near train tracks serving the French capital's busy Gare du Nord station, triggering cancellations and leaving travellers heading to and from Paris stranded.