Train services across central Scotland are facing disruption due to a signalling fault near Edinburgh.
The fault was discovered in the signalling system between Linlithgow in West Lothian and Edinburgh Park on Wednesday afternoon.
ScotRail said delays were likely until 7pm.
Services between Edinburgh and Glasgow Queen Street via Falkirk High will be reduced to a half-hourly.
Trains between Edinburgh and Dunblane are also being reduced to hourly.
ScotRail said: "We've got a fault with the signalling system between Edinburgh Park and Linlithgow and unfortunately we're unable to run a full service."