Scotland's railways are facing further disruption as a result of the flooding which caused chaos for travellers in parts of the country.

Railtrack engineers have launched a massive operation to repair the damage on the line between Glasgow and Edinburgh.

Services will continue to be affected over the weekend - and ScotRail has delayed plans to return to running four trains an hour between the cities.

We were not prepared to take risk of added inconvenience to our passengers

Peter Cotton ScotRail

The monsoon-like conditions which hit Scotland on Tuesday caused havoc on the rail network.

The main artery between Glasgow and Edinburgh was badly hit by landslides and track circuit problems.

Railtrack said everything possible was being done to get the route back to normal.

Its engineers are working to repair two landslips on the approach to Glasgow's Queen Street Station and track circuit problems at both the Queen Street tunnel and the Haymarket tunnel in Edinburgh.

The high level station at Queen Street will be closed on Sunday to allow access for engineers.

Cast-iron guarantees

However, ScotRail said there was no guarantee that the work would be completed in time for Monday morning.

As a result it has postponed the reintroduction of the quarter-hourly service between Glasgow and Edinburgh until Tuesday.

"It's not a decision that we've taken lightly," said acting managing director Peter Cotton.

"But Railtrack have a huge programme of work to carry out and were unable to give us cast-iron guarantees we need to reintroduce the 15 minute interval service.

The east end of Glasgow was hardest hit by flooding

"With all these extra trains scheduled to run, the slightest engineering delay could wreak havoc on morning peak services and we were not prepared to take risk of added inconvenience to our passengers."

On Sunday, all trains which usually use Queen Street will be diverted to Glasgow Central, with the exception of West Highland line services which will be re-routed into Queen Street low level.

The Glasgow to Edinburgh service will be cut from half-hourly to hourly.

Elsewhere, the Highland line between Aviemore and Inverness is due to reopen on Monday following the major landslip at Slochd summit.

It has been estimated that the total bill for the damage caused by the flooding in Glasgow will run to several million pounds.

Finance Minister Andy Kerr has promised an investigation into why parts of the city's east end were so badly affected.