Three Eurostar passenger trains were stuck in the rail tunnel between Britain and continental Europe, a spokesman for the operator said today.

The trains broke down due to the cold weather snap affecting the region. The difference in temperature between the chilly open air and the warm tunnel under the English Channel caused the trains to break down.

Eurostar will be running a reduced service Saturday daytime due to the snowy conditions, the spokesman said, urging passengers to reconsider travelling if their journey was not urgent.

"Because of the weather, the snow and the extreme cold, we have severe problems with our trains," the Eurostar spokesman told AFP.

"At the moment we have three trains stuck in the tunnel and we are trying to get them out with a rescue locomotive."

The three trains, all from Paris to London, were in the same tunnel. Two further trains from Brussels and Paris heading for the tunnel had turned back, the spokesman said.

Cold outside, warm inside

The high-speed passenger trains stuck in the tunnel were fairly full, he added.

"It's really technical problems due to the bad weather and the snow. The difference in temperature is quite significant," the spokesman explained.

"It's very cold outside and it's very warm in the tunnel so there's a big difference in temperature and that makes it difficult."

Eurostar said the disruption to services would continue throughout Saturday.

"We strongly advise passengers not to travel. Because of the bad weather, we will have a reduced service.

"People can get a refund if they want or they can exchange their tickets for travel on a later date.

"Some of the trains will be cancelled. We will have a service but it will be reduced and so if their journey is not essential then we advise people not to travel."

Eurostar's British train drivers and staff began a 48-hour strike on Friday. However, the firm had enough drivers of other nationalities to cope, it said.

The Channel Tunnel runs for 50 kilometres between the county of Kent in southeast England and the Pas-de-Calais department in northeast France. Opened in 1994, it is the world's longest uninterrupted undersea link.

There are two rail tunnels - with crossover points between them allowing trains to switch from one to the other - and a service tunnel in the middle.

Besides the Eurostar passenger trains, the tunnels also carry freight and vehicle shuttles.

The passenger trains from London, which hit speeds of 300 kilometres per hour, can reach Paris in two hours, 15 minutes and Brussels in one hour, 51 minutes.

- AFP