Travellers consume food and drinks offered by staff at St. Pancras Station in London after learning the Eurostar train service between Britain and France had been suspended. (Akira Suemori/Associated Press)Eurostar has cancelled its service until further notice after a series of its trains malfunctioned in the tunnel between Britain and France.

Five Eurostar trains broke down Friday night, leaving more than 2,000 passengers stranded overnight. On Saturday night, a sixth Eurostar train with 750 people on board failed.

The company suspects that condensation formed after the trains left the icy cold air of France and entered the warmer tunnel, causing electrical failures.

A number of passengers have complained that staff seemed to have no emergency training.

"At one point, I asked for water for people in the carriage, as people were extremely thirsty," one man told BBC News. "It took them over an hour to bring us half a litre of water to share between 50 people."

Eurostar spokesman Nick Mercer said the company would be running test trains in the tunnel on Sunday "to get to the bottom of this, really, quite abnormal situation."

"This is the first time in 15 years that we've encountered this problem. We run something like 20,000 trains a year, and this is the first time this has happened," he said.

In addition to the 2,000 people trapped in the tunnel Friday night, a further 31,000 had had their trips cancelled Saturday, and 26,000 more were expected to be affected Sunday, a company official said.

With files from The Associated Press