Bosses blame "traction problems"
A Eurostar train is reportedly stuck in the Channel Tunnel after suffering traction difficulties.
The company insisted the break-down had nothing to do with freezing the temperatures sweeping across Europe.
The service from Brussels was expected at London St Pancras at 8.56am but ground to a halt about 20 minutes earlier.
A spokeswoman for Eurostar said: "There is a train delayed in the tunnel but it will be on the move again shortly."
ABTN understands another train was sent to tow the broken down train out of the tunnel.
Last month Eurostar faced a public dressing down after more than 2,000 passengers were stranded for more than five hours after trains suffered electrical problems brought on by the freezing conditions.