Trains are delayed between Wakefield Westgate and Doncaster because of signalling problems.
The disruption is between South Elmsall and Fitzwilliam.
Trains between Doncaster and Wakefield Westgate may be delayed by up to 20 minutes to at least 6pm.
Journeys between Moorthorpe and Wakefield Westgate may be diverted, not calling at stations between Meadowhall and Wakefield Westgate.
A bus will run from Wakefield Westgate to Bolton-upon-Dearne, calling at all stations.