Passengers on several Eurostar trains faced delays and cancellations on Monday after a power supply issue on a rail line in northern France led to its closure.
According to the Eurostar website, nine services between London and Paris were cancelled, while most other services were delayed.
The problem started at about 08:30 local time (06:30 GMT) on Monday and continued through much of the day.
French track network operator SNCF said that it had identified the issue and work to repair it would continue overnight, while Eurostar said it expected normal services to resume on Tuesday.
Some services between Brussels and Paris and between Amsterdam and Paris were also cancelled, delayed or faced other disruptions due to the rail closure, which happened on the high-speed line between Moussy and Longueil in the Hauts-de-France region.
Trains between London-Amsterdam, Brussels-Amsterdam, Brussels-London and Brussels-Cologne were not impacted.
SNCF said on its website that the "severely disrupted" services were due to a power supply issue which required "major repairs".
It predicted delays of between one and five hours on the Eurostar, as well as its other services TGV inOui and Ouigo.
Later, on Monday evening, SNCF announced that the closed section of the line had reopened on a single track in both directions. Normal services were not expected to resume until the end of the day.
August is a peak period for cross-Channel travel due to school holidays, meaning services are often busier than normal.
Monday's disruptions came nearly a month after a Eurostar train travelling between Brussels and London had to be evacuated in northern France due to a power failure.
And in June, there were two days of major disruptions after separate fatal incidents on France's LGV Nord line, which was followed by cable theft.
14 PerFlyer