Eurostar tweeted shortly before 8.50am that a rescue train had arrived and passengers were waiting for security procedures to finish.
At 5 a.m., 700 people were still stranded on the banks of the Calais-Frethun station due to “the presence of trespassers on the tracks at the French entrance of the Eurotunnel site”, Xinhua quoted Eurostar official as saying.
Eurostar later pulled the train back to Calais, where passengers disembarked for fresh air and bottled water.
A Eurostar spokesman said passengers should expect a normal service on Wednesday, but added two trains were cancelled “in order to ensure the service is as robust as possible”.
EU interior ministers are to hold an emergency meeting on September 14 to discuss the migrant crisis, with Germany and other nations urging Britain to do more to deal with the hundreds of thousands of people fleeing Syria and other countries.
Passengers on one London-bound train, which stopped less than a mile (1.6 km) from the tunnel, were told at one point to keep quiet and listen for people on the roof.
Without air conditioning or lights, conditions on the train deteriorated to the point that some passengers threatened to smash the windows and escape.
A Eurostar spokeswoman acknowledged it had been a frustrating time for passengers, and apologised for the inconvenience caused.
“At 4am they told us a train would be arriving to take us back to London”. “This is a weakness at the moment and as we have described numerous times the Frethun train station is just like [any other] train station we would have here so migrants can access the tracks”. A helicopter with a searchlight then circled the train as guards walked the tracks looking for migrants, but seemingly none were spotted. Railroad staff “were scared that that if they opened the doors, the migrants might attempt to board the train – potentially putting the safety of those on board at risk”, according to the Daily Mail.
Eurotunnel said most of the migrant intrusions were now happening outside the Channel Tunnel perimeter.
But reports of trespassers on the tracks and on trains outside the French port town of Calais on Tuesday night affected hundreds of holiday-makers, seeing some Channel Tunnel services delayed or cancelled outright.
Commuters stranded in France spoke of being “surrounded by migrants”, including some who had climbed on top of trains, and branded the situation a “fiasco”.
The crossing at Calais has been plagued with problems all summer amid a growing migrant crisis. France sent 120 riot police to the region at the end of July and Britain provided £7m ($11m) in security measures to protect the Eurotunnel terminal at Coquelles after 2,000 attempts were made by migrants to storm the tunnel in one night.