Hackers broke into and distorted Railtrack's internet home page on Friday as a Y2K prank.

The website provides online timetable information for travellers using the UK's railway services.

The message from the hackers read: "Sorry, but due to the Y2K compatibility problems there will be no trains operating between 31-12-99 and 02-01-00."

The hackers then sent their greetings to "all the Railtrack directors, all the sheep in Wales" and acquaintances with names like HackUK, Rootworm and Slacker.

Railtrack quickly corrected the site. A Railtrack spokeswoman said: "This is a prank that is supposed to be amusing.

"Unfortunately it will affect hundreds and thousands of people who are trying to get into London for the millennium eve celebrations.

"We would like to reassure all our customers that trains are running as published."

Railtrack has spent four years checking and correcting its computers.

The company, which is responsible for the all the track, signals and some stations in the UK's privatised rail network, was deemed to be 100% compliant under the government's Action 2000 millennium readiness "traffic light" assessment process.

It is also operating a command centre through to the end of March to co-ordinate Year 2000-related problems that crop up.