"A practice has damaged down within the tunnel and we're within the strategy of transferring prospects to a separate passenger shuttle through the service tunnel, to return to our Folkestone terminal," Eurotunnel tweeted late Tuesday (early Wednesday AEST).
"We apologise sincerely for this inconvenience."
Eurotunnel Le Shuttle runs trains that carry passenger and freight autos via the tunnel between England and France.
The breakdown affected the three.50pm (11.50pm AEST) service carrying lots of of individuals and several other canine from Calais, France, to Folkestone, England, the PA Media information company reported.
Passenger Michael Harrison advised PA concerning the unnerving expertise.
"We obtained on the three.50pm crossing, roughly 10 minutes within the lights went out and the practice stopped," he stated.
"We have been advised they wanted to research a difficulty with the wheels."
He stated it took about an hour and a half for employees to research with out discovering any issues.
"They reset issues and set off for an additional 5 minutes," he stated.
"It occurred once more at which era we waited an extra couple of hours to resolve they could not see an issue however needed to evacuate the practice to a different practice."
Passengers have been then evacuated via the emergency hyperlink tunnel to the service tunnel, strolling for about 10 minutes till they reached one other practice, Harrison advised PA.
Additional points with the alternative practice meant passengers lastly arrived within the UK six hours after boarding, he added.
The Eurotunnel Le Shuttle service usually takes 35 minutes to make the journey between Folkestone and Calais.
A second passenger advised PA "a number of folks have been freaking out about being down within the service tunnel".
"It is a bit of a bizarre place," they stated.
"We have been caught down there for at the very least 5 hours."
Fellow passenger Kate Scott stated temperatures within the tunnel have been a difficulty.
"It was sizzling, there was no air conditioning, they gave out water however we did not actually know what was happening," she stated.
Sarah Fellows, 37, advised PA "the service tunnel was terrifying".
"It was like a catastrophe film. You have been simply strolling into the abyss not figuring out what was taking place. All of us needed to keep beneath the ocean on this large queue," she stated.
"There was a lady crying within the tunnel, one other girl having a panic assault who was touring alone," added Fellows.
"They have been anticipating actually older folks to stroll for a mile down the center of a tunnel beneath the ocean.
"I used to be panicking at one level and Border Pressure advised us the tunnel had been evacuated one different time within the final 17 years, not not too long ago."
The problem additionally had knock-on results on later companies.
"As a result of earlier practice fault, we advise you to not journey to the terminal tonight," Eurotunnel stated in a separate tweet late on Tuesday (Wednesday morning AEST).
"Please arrive after 6am tomorrow."
On Wednesday morning, the corporate stated trains have been operating once more.
CNN has contacted Eurotunnel for additional touch upon the incident.
The Channel Tunnel revolutionised journey between the UK and mainland Europe when it opened in Could 1994, making the journey far quicker than the equal ferry route.
It had been mooted for greater than 180 years earlier than British and French employees broke floor and commenced digging towards one another in 1988.
It took six years for 13,000 employees to construct the 50-kilometre tunnel, 37.9 kilometres of which run undersea, making it the longest of its sort on the planet.