An unexploded bomb from World War Two has been unearthed near Paris Gare du Nord station, and all Eurostar services between London and Paris have been cancelled, along with many domestic train services in the Paris region.
Eurostars are continuing to run from London to Brussels and Amsterdam, but trains between Amsterdam and Paris have also been cancelled.
The discovery of the bomb near Saint-Denis was made during work overnight.
Eurostar has apologised for the disruption.