A fire in a truck being transported through the Channel Tunnel triggered an alarm which led to suspension of all passenger and freight rail services between Britain and France on Saturday, police said. No injuries were reported.
Kent Police said the fire was at the French end of the tunnel.
Eurostar said rail passenger services between Britain and France were suspended after smoke was detected in the tunnel beneath the English channel. Tunnel operator Eurotunnel said in a statement that a C02 alarm went off just before midday and that it was investigating the cause.
We are sorry but we are unable to run any further trains today because Eurotunnel has been closed due to smoke detected in the north tunnel. If you were planning to travel today, we advise you to postpone your journey and not to come to the station.
On its twitter account Eurostar has been advising passengers on refunds, and that service may not be restored until this evening.
Sky News reported that the Cross-Channel car service Le Shuttle tweeted: "CO2 detectors have been activated in one tunnel; we are currently awaiting feedback from teams in Tunnel. Further info to follow."
In March, hundreds of Eurostar passengers were delayed after a lightning strike triggered a fire in a building close to the entrance to the tunnel in Kent.
Although there was no damage to the track, four trains in and out of England were affected.