Passengers were left stranded in the Eurotunnel after a train broke down inside.
Video shared on social media appeared to show travellers walking along the central service tunnel after their train broke down en route to France on Tuesday evening.
A spokesperson for Eurotunnel Le Shuttle said: “A train has broken down in the tunnel and we are in the process of transferring customers to a separate passenger shuttle via the service tunnel, to return to our Folkestone terminal.
“We apologise sincerely for this inconvenience.”
Passengers reportedly had to abandon their vehicles and were being escorted on foot.
The Eurotunnel is a 31-mile railway tunnel that connects Folkestone in Kent with Coquelles in northern France.
It is the third longest railway tunnel in the world and has the longest underwater section of any tunnel in the world.
Olivia Pratt-Korbel latest: First images of girl, 9, killed by gunman in balaclava who reached through door and ‘shot blindly’
Olivia Pratt-Korbel, 9, killed in Liverpool after gunman chased man into her home
Gatwick cancels easyJet flights at last minute after declaring ‘business as usual’
Tuesday’s incident follows a similar episode back in April when a train broke down in the tunnel at the start of the first school holidays since COVID-19 travel rules were scrapped.
Eurotunnel detected a safety problem on a freight-only train which needed to be fixed inside the tunnel before being taken back to Kent, blocking one of the two tunnels.