A security exercise has been staged in the Channel Tunnel by police, fire and ambulance services from both England and France.
Services were suspended and customers informed
Eurotunnel said it was to test the co-ordinated emergency response if an incident were to occur in the tunnel.
A spokeswoman said it was to simulate a "particularly demanding problem" on board a train, and involved nearly 300 extras, assessors and observers.
Services were suspended overnight and customers were informed, she said.
There have been 12 such exercises since 1994, she added.
This year, the exercise was being led by authorities in France.
The exercise on Saturday night included four Eurotunnel shuttles and six buses.
"Maintaining the highest level of safety has always been and remains a fundamental priority for the group," the spokeswoman said.