The Eurotunnel car shuttle from Britain to France came to a halt at about 7:30 am (0630 GMT), about a quarter of the way through the 50-kilometre long tunnel, after a problem with the overhead power supply, a spokesman said.
The 382 people and four dogs on board were transferred to the French terminal, where they should be reunited with their cars once their train can be moved.
"It will take a while to get sorted," a Eurotunnel spokesman told AFP, adding that passengers were advised to travel another day or, if already at the terminal, to take the ferry across the Channel.
He said it was a "purely technical incident".
Also Read
Eurostar, which runs passengers trains through the tunnel between London, Paris and Brussels, said it had cancelled six trains today between 10:13 am and 1:13 pm.
"There is only a single line working in the tunnel while they fix the catenary (overhead power supply). We've had to cancel some of our trains to take that into account," a spokeswoman said.
She also urged passengers who do not have to travel today to change their tickets, free of charge, for another date.